I agree with the vast majority of your reasoning and I like your scenarios. BTW, Texas beat Oklahoma at the end of regulation, not OT.
Though, for us to get in, I don't think we need both ND and Oklahoma to lose. Rather, either one of them losing will open the door for Ohio State to get in. However, if both of them lose, then, yes, I think we definitely get in. (BTW, I am assuming in this scenario that Ohio State wins out.)
Like you said, Alabama needs to win out. A 1-loss Alabama team just opens the door for a second SEC team to get in.
I doubt Ohio State wins out, though - especially not the way they look, all the turmoil that's occurring right now, etc. There's a good chance Michigan State beats them, NW has a great shot of beating them, and Michigan may hand them their worst loss in Ohio Stadium. Thus, I am kind of rooting for chaos, like for Alabama to lose twice (LSU this weekend and then to Auburn), Kentucky to win the SEC, Washington State to win the PAC, Northwestern to win the B1G, and West Virginia to win the Big XII. Just absolute craziness.
My want scale kind of goes like this:
1) Ohio State to win National Championship
1.5) Ohio State to win NY6 bowl game
1.75) Ohio State to win B10
2) Alabama to NOT win the NC
3) ND to NOT win the NC
Maybe it's just me, but I see a bunch of similarities between this team and Meyer's Florida team(s) that spiraled out of control. Like, the cracks are showing and it seems like only a matter of time before the dam breaks. Hope I'm wrong.