As I've always interpreted is that Jedi resemble Buddhist monks more than any other earthly religion. That means that they view is that all desire leads to suffering and if you master emotion the only thing left is compassion and peace. Jedi also believe in maintaining a system of power in which everyone benefits and where leaders cannot become all powerfull. To do that, they need a certain amount of power and to not become rulers themselves, as the Sith do, they try to give up all their attachments and their ego. This let's them make decision as a peace keeping force that serves purely to protect, without becoming corrupt by the lures of power. I don't think that using the Force better or worse has anything to do with it, but more with the way that the Force SHOULD be used. Eventually that inner peace that they gain by mastering emotion, gives them a certain 'cool' in battle which leads to a very efficient way of using the Force.

The PTS guys probably, I haven't been on Yes

The only thing you miss out on is that if you select romantic options when she pops a quest after gathering a certain amount of affection, she gives 800+ points. It popped up for me around 3 times or so. If you keep her around long enough and give jedi answers to questgivers, you should be fine too, 100 points a pop whenever the force is mentioned takes you there quite fast too

I stumbled inside by accident, but it had a Trooper only instance in it. IIRC it's at the Avian Park, southside, but I could be wrong