To the best of my knowledge (and I'm very much invested in EDs decision on this so I've been watching very closely but may have missed something) he hasn't said anything about the US mobile market at all.
It depends. I still have to dive into the US mobile market to find out what you need, but I know the module supports at least a few of your frequencies.
Microsim. You can use a converter to use a nano-sim and you could cut the large sim into a mirco one (phone provider shop usually can do that for you if you don't want to do this yourself).