1) I certainly don't try to hide. I play for fun, and hiding is not fun for me.
In fact, quite the opposite. Ganking some seventies with my lower-level shamans seems to be quite relaxing after a long day.

2) Putting unpleasant people on ignore Makes bg very pleasant. I do not remember getting hate whispers, mostly whispers are people talking in an open chat - general or bg. I get the most hate in bgs, but during the first minute or two of bg, I put anyone who seems to be cursing or otherwise talking trash to anyone on ignore. Haven't had any problems so far.

3) probably a lot. Probably at least 5 or so times, but so far a GM has never bugged me, and I've never had to prove anything. I have read one or two reports here of folks having to put up with trash, but that is usually something else.