I'm still a little sketchy on penalties with a double blade. I have increased my Dueling Feat and I guess because of a glitch this doesn't penalize me for using a double bladed sabre, but does it offer me a benefit or is it just a wasted feat?

Dueling affects only a single weapon in a single hand: a pistol, single saber, unarmed etc but it does not affect rifles, as even though theyre single weapons theyre held in two hands. It adds +1 Attack, +1 Defense per rank

Two-Weapon Fighting is the feat that reduces the dual wielding penalty to Attack from using a weapon in both hands or a double bladed weapon like a quarterstaff or dual-saber

Some people say Dueling isn't worth the feats. Some say the penalty to Dual Wielding isn't so huge after wearing the best gear (or crafting it in KotOR2) that it isn't worth 3 feats.

Dueling is cool for fist fighters in KOTOR2.

And Kreia; for obvious reasons...

Everyone in those movies gets prosthesis but her. Never could figure that out. :P

Both feats are an absolute must for me.

If you're playing with a close-combat fighter, you'll have more feats than you need and since you're fighting with lightsabers anyway, there is no real reason to exclude them.

If you're using force-powers, your skill with the lightsaber won't really matter at all, so you could skip those feats. But there is of course always the roleplaying aspect and I feel like it's kinda illogical that you fight without getting better with your choice of weapons, or that you don't train to get better with them, however you'd like to put it.

But, combat is easy enough anyway in KotOR and you can do whatever you want.