The broadcaster has the commercial slots listed by the price. The earlier commercials are more expensive. The companies pay per slot - so its a mutual decision between the broadcaster and the companies.
No just NBC.
The 2015 Super Bowl network has not yet been announced. Usually the Super Bowl will air on either FOX or CBS.
In India, since Super Bowl 42 was carried on TEN Sports. Finally NFL Football will air on these two channels. ESPN HD Star Sports (Standard Definition)
Super Bowl 43 will air on NBC at 6:25 PM ET.
Yes, ABC aired the 2009 Super Bowl.
It is a joint decision between the NFL and the network which will air the game. It is always scheduled against a prospective "contender" and preferably a team that is less than 2-3 years removed from a super bowl appearance.
CBS
CTV
Fox
Fox
6pm e.s.t.
CBS