I can answer 2 of your more generic questions.
A class 1 medical can be renewed in Florida, only the initial needs to be done at Gatwick. If you are considering commercial training and do not yet have a class 1, do it now!
A J-1 visa does allow your partner to wrk, up to 20 hours per week I think it is, or at least that was the case when I had a J-1 visa several years ago.
Hope that helps a little, and good luck with it.