Hypothetical NCAA OT penalty situation

[bearclause]

Last weekend I went to a single OT game won after a team:

1) Scored a TD and extra point in the first series.
2) Sealed the victory with an interception in the second series.

However - the intercepting defender kept on running and was tracked down at the opponents' 15 yd line. The final margin of victory was 7 points.

A bunch of us interested fans have gone over Rule 3-1-3 (on extra periods) in the 2006 NCAA Football Rules. Particularly intriguing are the parts dealing with post change of possession, where most penalties are automatically declined and it's stated that there can be no additional 1st and 10. We're wondering what happens in the hypothetic OT situations where:

a) Team A (original offensive team) member commits a post-interception penalty that prevents a Team B member (who intercepted the ball) from potentially scoring. My reading suggests that the play would be over, and the only penalty enforcement would be on a personal foul/unsportsmanlike conduct if the game is not yet decided, and only on the next play (2nd series or beginning of new OT period). In our case it would obviously be over, but what happens if it's in the first series?

b) Team A manages to recover the ball after it's fumbled by a Team B player who originally intercepted the ball. Members of Team B think it's over and start wandering onto the field. Is is possible that Team A would be given a replay of the down for illegal participation? My interpretation of the NCAA OT rule is that pretty much all fouls are declined and nothing can force a replay of a series after the initial turnover, although a score can be cancelled if the scoring team commits a foul. I've heard some suggestions that it only makes sense to allow Team A to replay the down where the ball is blown dead plus the penalty yeardage, although the rules don't seem to address that possibility.

c) Same as B, but maybe one Team B player not originally participating in the play sees the ball is still live and tackles the Team A ball carrier. That would seem to clearly be a case where the referees discretion to award a score could be possible. I'm still wondering if the discretion to replay the down is applicable given that the rules otherwise state that an OT series is over once there's a turnover, and is there really any replaying of the down on a change of possession?