Lots of questions there. I'll try to address each one.
Under the 12-team proposal, teams could play a maximum of 17 games: 12 regular-season games, conference championship game, four playoff games. In the FCS, teams that win the national championship end up playing 16 games.
Conference champions are decided by their conference championship games. All 10 FBS conferences now play a title game. The 12-team model includes the six highest-ranked conference champions - so they will use whatever ranking system is decided to rank teams after the conference championship games are played.
Under the proposal the first-round games would take place on campus during the two-week period after conference championship games. The quarterfinals would be played on Jan. 1 or 2. The semifinals and championship game dates are to be determined, though the semifinals "likely will not be played as a doubleheader."