I've played SWG on and off over the years, and as far as MMO communities go, it's pretty decent. You can't judge the SWG community from the online forums...ye gods, those forums are a troll magnet

...as most players don't post on the forums. However, for the most part players are very helpful and nice ingame, as you will see for yourself if you decide to play.
One very nice feature about SWG: PKing can only happen if you consent to it. There are two ways for players to fight each other: one is through factional (Rebel and Imperial) PvP, and the other is via Duel. You can decline a duel if you wish - you aren't forced to accept it. It's a decent compromise IMO. Some people play for the PvP element, while others don't care for it. Myself, I binge PvP. For weeks I will do nothing but PvP, then chill out for a while and stick to NPCs and critters, and quests.