I will update my thoughts of the skills. Essentially, I am even more pessimistic and disappointed in the design of the class than I was at low levels
Primary
Hungering Arrow. Big, single-target damage, at absurdly long range, but nothing else. The Runes just add more DPS, which means (a) it is always dull, and (b) everyone will just pick the highest DPS option (Hungering Arrow). Probably a little too powerful for a Hatred-generator, but so incredibly dull to use.
Entangling Shot. Low damage, but can potentially hit two (or more) targets
if they are close enough. The range on that is a little too low in most situations. Snares, but by Hell difficulty the Snare effect is a little too heavily scaled reducing its usefulness. Again, all the Runes are utter garbage.
Bola Shot. High damage, with a small AoE, but only after a delay. This one actually has an interesting selection of Runes that allow it to be customised, though most of them are a little weak, even for a Hatred generator. The delay before it explodes means it forces a significant shift in play-style.
Grenades. Solid damage with a good AoE, but there is a delay between firing and the explosion, and the grenades can bounce around off terrain. Also has some interesting Runes, but the unusual style makes it a little awkward to use as a Hatred Generator.
Secondary
Impale. A really solid, powerful option, but definitely too Hatred-expensive. Has some interesting Rune options, but all of them are over-shadowed by Impact, the only Rune that almost justifies the absurd cost. Would require support from an AoE option (ie Multishot) to deal with regular trash mobs, but is utterly devastating against brutes and Elites.
Rapid Fire. Pretty bad in Normal; only gets worse as the difficulties progress. Obliterates your hatred in seconds for average damage, and at the added cost of almost certainly screwing yourself over. Only the Withering Fire Rune, for its reduced cost, makes this even conceivably useful, but even that does not justify a skill that is fundamentally flawed.
Chakram. Only useful with Twin Chakrams, and only until you unlock something better. The odd aiming combined with Diablo III's fast and highly mobile mobs makes this far too unreliable to justify. Most of the Rune options actually make it less reliable, making this an awfully designed skill.
Elemental Arrow. While lacking the heavy-hitting of Impale, this skill provides a solid AoE, making it perfect for dealing with Trash Mobs at minimal Hatred cost. Honestly, most of the Runes have their purpose. Electricity for larger AoE, Ice for damage and Snare, Fire with a (perhaps too small) chance for a Fear effect, and Shadow for (again, too small) life leech. Not as good against Bosses or Elites as Impale, but a great option for trash mobs and brutes.
Defensive
Caltrops. I loved this in Normal, but I struggle to make use of it later. Borderline-useless for people using Entangling Arrow, as they both do much the same thing, but more appealing with other options (perhaps especially Bolas and Grenades, making up for their delay). Most of the Rune options are quite interesting, but the hard thing with this skill is its tactical application. Combined with the faster mobs of Hell and Inferno, as well as their natural resistance to Snares, this would be a difficult skill to take advantage of.
Smoke Screen. Despite being nerfed twice, this is still the de facto choice for most Demon Hunters. Immunity to damage and control effects, along with Root-Break, this is the all round defence for all situations. Combined with the Tactical Advantage passive, it is also a fantastic tool for positioning. Basically all the Runes are useless, however, making Lingering Fog's minimal boost the only one really worth considering (unless you have a bit of +discipline gear, where Special Recipe may be worth considering).
Shadow Power. Despite sounding so very high, the life leech on this is actually provides minimal advantage. The extreme fragility of the class in Inferno especially makes it quite pointless. The only Rune that makes this borderline useful is Gloom, which still provides minimal benefit. Compared to the advantages of Smoke Screen, it is hard to justify using Shadow Power: longer effect, but a dramatically weaker one.
Hunting
Vault. Sadly, not as good as it looked. The delay at the start of the animation makes it a poor panic button, the delay at the end of the animation makes it highly risky to use, and the fact you take damage while moving makes it pretty well useless --- especially against Molten or Poison Elites.
Preparation. A perfect example of terrible design. Tactical Skills were considered too powerful, so they created Discipline to prevent them being spammed. Discipline becomes a terrible handicap for the class, so they add a skill to allow Tactical Skills to be spammed. WTF? Sure enough, the only purpose behind this skill is to exploit how powerful the tactical options are (namely, Smoke Screen through an entire encounter). On basic design, this was a terrible, terrible idea; in practice, it is likely critical for any exploitative build the class may have.
Companion. A pretty poor option, all in all. The AI is awful and the damage is weak. Most of the Runes add nothing useful. Except the Bat. Suddenly, an awful Active Skill becomes our only decent Passive Skill. Almost doubling the Hatred Regeneration means a lot of our over-priced skills become highly viable options. You can guarantee Blizzard will nerf this to oblivion in 1.1, but until then there is no reason to not use this.
Marked for Death. An interesting option, but one I have not really used much. Most of the Runes have interesting applications, and the basic effect of the skill is nice. Sadly, I think that is also its problem: it is `nice', but not `OMG look at how sweet this is!'. It is just not exciting for an active skill. Probably should have just been left in D&D.
Devices
Evasive Fire. Oddly, a Hatred generator that is not classified as Primary. In general, an odd skill. The attack is dull and does not offer anything that cannot be done better by other skills; the evasive aspect of it is quite weak, often entirely ineffectual at higher difficulties, and does not work as described. The Runes are quite dull, providing nice options to an already niche option. No matter how much I try, I just cannot justify the existence of this one.
Fan of Knives. An interesting skill, with some interesting Rune options, but it is never very good. I tried using it for Vortex, Teleporting or Fast Elites, to tag some damage before I used Smoke Screen to run off. It was `free' damage while I focused on movement, but not overly good damage. The short range made it often miss too, making Hail of Knives essentially necessary, but at the loss of any interesting effects.
Spike Trap. Another one I tried considerably to use, but just could not justify. Essentially, the damage was just not very good for a skill that takes so long to set up, costs so much Hatred to use, and requires tactical application to make enemies even walk over to be effected. None of the runes really solved the issues I had with it, making it something that sounds nice, but I never really found added value.
Sentry. A fantastic-sounding option, but very disappointing. The base damage is pitiful, making it almost useless by itself. The Runes add interesting tactical options, but suffer horridly for range. Probably much better in co-op situations, but in solo it leaves me wanting.
Archery
Strafe. ``What is this? I don't even know.'' That is the only way I can describe this. It costs hatred, does poor damage, has so-so targeting and slows your movement. Does it actually serve a practical application? Without dramatic changes, I very much doubt it does.
Multishot. The primary AoE option for Demon Hunters. Decent damage, but more importantly it hits a very large area very quickly. A little too expensive, but Fire at Will completely solves this issue making it spammable, allowing you to obliterate trash mobs and Minions with ease, allowing you to focus on brutes and Elites with harder-hitting and/or cheaper skills. Sadly, the high cost makes other Runes hard to justify, though they certainly can be built around.
Cluster Arrow. Powerful, but absurdly expensive, and the grenades with it are so random as to be useless more often than not. The AoE of the initial hit seems very small, making the grenades a critical part of its function, but their unreliability makes this a poor choice. Many of the Runes replace the grenade effects, but the skill is still to expensive to justify them
Rain of Vengeance. An interesting skill that takes the approach of making each Rune truly unique. I have mostly used Dark Cloud, which allows you to put some decent damage on enemies you are kiting. This seems largely useless in co-op, however, and can also sometimes attack terrain instead of enemies, again reducing its usefulness. The other Runes seem tailored for co-op, but none of them seem very useful in my experience. The design of them just does not seem to correlate with the design of the rest of the game, leading to much of the damage being wasted.
Passive
Tactical Advantage. A nice enhancement to Smoke Screen and Vault; well worth considering if you use either. As mobs get faster over the difficulties, this becomes increasingly useful.
Thrill of the Hunt. An interesting option, but not especially useful. Once in a while, one enemy will not chase you; sadly, his 20 friends still will. Highly situational and entirely uncontrollable.
Vengeance. Extra Hatred is nice. Hatred and Discipline from Health Globes is OK, but pretty situational. Sometimes it will save you; others it will do nothing to help.
Steady Aim. Extra damage. It does not work if there is an enemy in melee range of you, but you are probably already dead by that point anyway. May as well just be a flat `bonus damage'.
Cull the Weak. A nice little bit of extra damage if you use lots of Snares (eg Entangling Arrow), but the boost is pretty small for such a situational skill.
Night Stalker. Perhaps could serve a meaningful purpose in certain niche builds, but the effect is pretty weak and too situational.
Brooding. Essentially, heal a little faster after combat; sometimes helps while kiting too. The effect is pretty minimal and there are too many enemies that invalidate it, making it too situational.
Hot Pursuit. Pretty useless. An extremely minor boost to speed that only works in situations where you do not need a boost to speed. Perhaps there could be a niche build for it, but largely useless.
Archery. An absolute must-pick for bows and a nice option for hand crossbows, but pretty awful for crossbows. It adds DPS, but your weapon of choice heavily effects how useful it is.
Numbing Traps. Probably most useful if you are making heavy use of Fan of Knives, as you are likely to be hit afterwards anyway. Has some benefits to Caltrops and Spike Trap, but is probably of more benefit in co-op than solo, as your allies can likely take a hit already, so 25% off will mean something.
Perfectionist. Pretty useless. Essentially, -1 Discipline on your tactical options. Woohoo? Even combined with the -2 Discipline Runes on those skills, the benefit is so small as to be pointless.
Custom Engineering. I have not used this one at all, as I cannot find any reason to justify its existence. It just does not add anything I think would be moderately useful.
Grenadier. I have heard of people using this to fuel suicide build throughout Inferno; I cannot say I would recommend it. Provides a nice bonus to Grenades and Cluster Arrow, which could be useful for a variant.
Sharpshooter. Stronger than it sounds, especially with slower weapons. Crossbow users should pick this over Archery; Hand Crossbow users will find it adds little. Still, extra DPS and can fuel `on critical hit' effects.
Ballistics. If Runes that added Rockets were more useful, this may be an interesting passive; as it is, it adds very little to some very niche options. Could be built around for an interesting variant, however.
May the wind pick up your heels and your sword strike true.