Sure - but the first order of business for B12 is a travel partner for WVU.... the does the B12 want to move to the mountain time zone? If they do that, wouldn't BYU make more sense?
CSU's biggest advantage is the potential for the Denver TV market.... unfortunately they haven't shown that they can bring eyeballs to their games. CSU has to hope that they continue to have success, and that this expansion talk drags on for 4 - 5 years, not 1 - 2 years.
There is logic to everything you're saying but, again, every school has blemishes. Every program that can be given real consideration has a relatively small fan base outside of BYU. You'd expect fan support to increase with a move to the Big 12 (playing OSU, KSU, and Texas is bound to have an effect compared to San Jose State, UNLV, and Nevada).
Cincinnati makes a lot of sense geographically and has a solid product on the field/court (which I think matters less than most people give it credit for). They would definitely be a front runner.
BYU doesn't want to play on Sundays, has a public perception of arrogance due to the whole recent move to Indy, is even further west than CSU, and offers limited benefit to Big 12 recruiting.
Memphis sustains success in basketball and now shows life in football, is good geographically, but isn't a great fit in terms of being academic peers to the other Big 12 institutions.
UCF offers the chance to break into Florida and has had recent sports success. Otherwise it isn't a great fit geographically and would likely to be interested in eventually defecting to more regional conference if given the opportunity.
Boise does have a good fan base (given their conference affiliation) but has limited success outside of football, is a horrible geographical fit, is perceived as gimmicky, and isn't an academic peer.
CSU is an institutional peer, football is hopefully on the rise, basketball has been fairly competitive recently, and will be building a new stadium, but is a poor fit geographically.
I'd guess that Cinncinatti, BYU, and CSU would be the first 3 considered, but I could just be seeing this through green and gold glasses.