I'm working my first character, a summoner, almost level 40.

My first question is about bane. I've used it a few times in dungeons and it seems when I do I pull aggro from the mobs. Should I refrain from using this in dungeons?

Secondly, how exactly does my limit break work? Is there a certain time I should be using it, and will using it take away the ability for another party member to use theirs at a more appropriate time?

Thanks, I'm sure I sound retarded but I'm still learning it all.