I want to build a powerful damage dealer with good survivability but find myself very clueless as to what to put skill points in.
My Lilith has both of those characteristics, but it heavily relies on being able to find some good SMGssome good SMGs. Even still, she can't approach the levels of damage dealing that my Mordecai can dish out, but she is much tougher to kill due to her boosted survivability.
Here is how my skills break down with ~56 skill points:
Controller Tree
- Diva x5 (Survivability)
- Inner Glow x5 (more survivability when escaping)
- Hard to Get x5 (more phasewalking is good)
- Girl Power x5 (More survivability)
- Mind Games x1 (just for fun)
Elemental Tree
- Quick Silver x5 (More DPS)
- Spark x5 (Elemental effects are good)
- Resilience x5 (survivability)
Assassin Tree
- Slayer x5 (crit damage = more dps)
- Enforcer x5 (more DPS after a kill)
- High Velocity x5 (more accuracy and damage)
- Blackout x5 (more phasewalking, but get this after hard to get)
For the last remaining 14 skill points (or so depending ho what DLCs you have), you can think about maxing out Mind Games and putting some points into Intuition/Radiance. I wouldn't recommend phoenix though, as the flame aura from that can cause nearby barrels to explode, which is a pain in the ass on some maps.
With this build you can shoot and shoot, then run away with phasewalk when your health gets low.
I haven't tried a pure melee build as I don't think it'd work that well, but I could be wrong.
Finally, make absolutely sure you find yourself a class mod that provides SMG ammo regeneration, without it you'll go through ammo waaaaay too fast.