Building availability contributes to pretty much all of the decision making, and then of-course, TV also effects. If NBC really wants two series on the weekend shown a particular way, some teams could actually start Friday too.
Celtics play on Wednesday, I know Bruins/Ottawa will start on Thursday/Saturday (You own HNIC Ottawa)
Yes. I would also assume that the Canucks will also start on Thursday (depending on availability) if they play a Pacific coast team. If they're playing Dallas, then Vancouver and Ottawa (if they make it) will alternate every day on HNIC.