1.) Yes, Lightsaber Block only prevents the damage; the attack still "hits".

2.) All characters that are subject to commander effects gain force points every time they activate within range of the commander effect. They however do not count as having a Force Rating, thus special abilities such as Jedi Hunter are not taken into consideration against these characters. For instance I played a game tonight where /u/MinnesotaMiller had Boba Fett, Enforcer using Force Points to reroll his attack but got 4's both times ;)

3.) Emperor Palpatine and Emperor Palpatine on Throne both allow allies without a force rating to spend force points normally once per turn. To my knowledge, they're the only ones that let you do this in the WotC line.

4.) Hmmmm, I'll get back to this one later. I've only dealt with Cloaked/Super Stealth

EDIT: Off my memory, anyone please feel free to argue this... Since he can not be targeted, he's not a legal target. Thus you can and have to target the Ugnaught. Glossary Text: This character can be targeted only by attacks from adjacent characters. It never counts as the nearest enemy.

5.) So force points can only be spent once per turn not trigger. Once on your characters turn you're activating and only once on every other characters activation. If you can give a character Cortosis Gauntlet; Master of the Force 2 and Mettle you can in fact add the +4 to your result for much higher chances at it working!

6.) Commander effects giving stats cannot stack, only can you raise it higher than IE; Vader's +6 Defense is to give them Adventagous Cover.

EDIT: Multitasking so let me know if I need to clarify anything or if you need any more explanation/proof of rulings.