The 1 seeds don't necessarily depend on conference, but the breakdown that keeps showing up is about right.
Kentucky, Duke, Arizona, and somebody will be the ones. That's pretty much set, barring a spectacular collapse from one of those 3.
Highly likely. The one among those three with the most competition in-conference is Duke, and ACC could end up with two 1 seeds if it splits regular season/conference, and neither Big 12 nor Big Ten champs get separation.