I prefer scrapping divisions, makes the scheduling more even and who makes the playoffs more fair. Option B or C. You still have something to play for, and one division makes it easier to tell who is in what division.
1-4 championship playoffs
5-8 consolation pick
9-12 avoid the spoon (can add another consolation pick for 9th too).
2 QB is quite a large change. My reaction is that I don't really like it, no real idea as to why.
As for defence, I have found that some good defences are getting punished because of a bad offence. But logically wouldn't a good offence also reward a bad defence, even if the measure was yards allowed? I'm not too fussed about it, it's just something yo have to factor in when picking Defence.