I respect your opinion but disagree regarding Brohm's ambitions. He's shown that he has a sense of loyalty and wanting to finish what he started, but ultimately I believe he wants to win championships at the highest level, i.e. National Championships, and that's just very difficult at Purdue relative to an elite program.
The Tennessee job is in no way wired to the Easy Button. They have great resources relative to Purdue, but expectations there are signficantly out of line with the reality of their situation and as long as Saban is at Alabama it's going to be tough going for other teams that expect to win SEC championships.
I think he'd have a hard time saying no to the Notre Dame job if Kelly left. If Day doesn't work out at tOSU and Brohm is wins a West title in the meantime I'd think he'd be high on their list. UM and PSU would be tough jobs to turn down. These are elite jobs, I agree that he's not likely to leave for less in CFB. With respect to pro jobs, I know that family is extremely important to him, but I'd expect that going to an organization that he believes is committed to winning and has the resources to do so would be more important.
These are good problems to have for Purdue. Hopefully Coach Brohm continues to drive improvement so that he stays on other teams' watch lists.