I agree with you about OSU. That's the only team where I think we'd have no chance whatsoever. The only way we can beat OSU with our current roster is if the Bucks decide they want to get rested up before the NCAA Tournament (decide to take BTT weekend off). Purdue'd probably kill us, too. I think the Boilers are starting to look like a legitimate national title contender.
For the most part we're pretty much locked into the 8-9 game. I think the only scenarios where the Gophers improve to the #7 seed is if we finish in an 8-10 tie for 7th with Penn State (winning tiebreaker by virtue of our win over Purdue, assuming Boilers stay in 2nd place) or if we finish in a 3-way tie at 8-10 with Michigan and Penn State. In addtion to requiring the minor miracle of the Gophers winning their last two, that would require Michigan losing at home to Sparty and Penn State dropping its final two games. Michigan would be #6 (3-1 vs. teams in the tie), the Gophers (2-2) would be #7 and Penn State (1-3) would be #8.
Even if that happens, playing Purdue (if we scrape by the 1st round) certainly would be no picnic.