1. Goes for everyone. Really it comes down to common courtesy. This is not endemic to one class or another.
2. Sure. Understand that time and experience are percieved linerally. In other words, there is a first time for everything. Watching videos and reading walkthroughs is excellent preparation...but there is still a first time. I ask folks to take that into consideration before sparking off at the tank.
3. I hate it when I mark 1 mob out of a 3 mob pull and they all die at the same time. If the tank marks, hit that. I'll play ball.
Tanks and healers...it's a seller's market. Do your best but don't fret. There is always another party to piss off.
