Alright so my lock will be 60 very soon

[Concillian]

Demonic Sacrifice is an excellent option. The only minor quibble is that you can't really sac your demon if you are on seduce duty in a 5-man (that being why I went back to Dark Pact.)

The first build: No Shadowburn, Bane, or Improved Shadowbolt, which will hurt nuke DPS quite a bit. So I'd think for 5-mans, assuming tank can hold aggro, the second build would be better.

Siphon Life is not useful for instances, nor is Fel Concentration .. Affliction in general is great for soloing and not so good for instances, where things tend to die too fast for DoTs to run. (An initial Immolate or Corruption is often all that you can really squeeze in.)

Oh yes -- Improved Drain Life is considered to be kind of crappy (improves only base Drain Life). Why not get Curse of Exhaustion + a couple of notches of improvement to play with instead? You won't want to slow things very often, but when you do ...

As someone who has played with a SM / DS build quite a bit, I'd call most of this accurate. Drain life and Siphon have some aggro issues, in that the DPS combined with the healing can get you in trouble sometimes. CoA is usually not in use in favor or CoE or CoS and Corruption may or may not be beneficial. Most of the affliction tree is wasted in instances.

I started out doing a lot of sac voidy in instances for low maintenance, but found that the health ticks draw aggro just like normal healing. You probably have the right plan with sac the succubus.

DS + SM with sac'ed succubus puts shadowbolt DPS in a good place. A little lower DPS than an SM / Ruin build, but not bad. very consistent damage.