Yea. I will agree with LordB. Global is usually bad. I tried chatting on there once and people are usually trolls. You don't really get serious answers a lot of time. The more helpful folks usually whisper to me the answers. It's hard sometimes to take anybody seriously in global.
Trade is pretty good.
As for negativity, I would just avoid chat. I hardly read chat. occasionally go on there for the in-game events or trivia if I'm available at that time.
That's what I usually do. Get into a good guild and guild chat instead.