Choosing the right alt

[kandrathe]

...
1. Has to level up fast and casually ...

Rogue, although no AOE, still the highest single target DPS if played right.

2. Deriving from point one but more specifcally in terms of cash flow: must have a reasonable killing speed.

Rogue, use stealth to get to Herbs, or Mining Nodes. If a mob comes along, Vanish. Skinner is also lucrative.

3. Being soloable of course.

Rogue, or Hunter.

4. Low dependency on gear, as I don't want to run instances to equip my alt properly. Running instances is what I do on my main almost exclusively and I need sometimes to do things on my own.

Rogue. Some kill damage is gear dependant, most is just skills and talents.

5. Having solid PvP qualities, just in case I need either to defend myself or get the sudden urge to gank someone  :shuriken:

Rogue.

6. Being fun to play  :)
Being a clothwearer is plus, since Melisandre is an accomplished tailor and thus can provide cheap gear upgrades.

You can make your rogue a cloak.

Play a rogue up to level 20, and if you don't like it try a Hunter. :-) And, don't worry about getting invited to play in instances. :-)