I know what your're going through. I had a bad experience the other morning. I was doing one of the random quest through group finder. Don't remember the mission. It's the one where you go through some sort of theater. Two of us said at the begining that we never did the quest. Anyway the other guy ran into a mob and the group wiped out. One of he jerks said if you pull again I'm leaving. Second time there was a part in the mission that required someone to man the cannon. They told one of us to man the cannon. I didn't know how to operate it. We wiped again (that was my fault). The two jerks were like, this ain't happening and then rage quit from the group. I sent a whisper to one of them and pretty much told them at least most of the other players I played with was kind enough to explain things out instead of barking out orders and rage quitting. After that i put both those clowns in my ignore list. This is one of the main reasons why I pretty much play solo and avoid joining any guilds. Don't have the patience anymore to deal with some brain damaged moron.
Anyway good luck in setting up a good guild. I hope everything works out for the best for you.
Hm...looks like I'm not the only one who had that problem with KAON UNDER SIEGE...
OP, what server are you on? If you're on Jedi Covenant, I'd love to join up with you when I do my random Hard Mode Flashpoints. I'm a tank, so you get the bonus of a STUPID FAST Group Finder queue in addition to someone who knows most of the Flashpoints already. (There are exceptions: I've STILL never done Lost Island, for example...)