A good start here and I look forward to seeing where you take it. It will be most interesting to see what they are like once all the things done to them are removed; I daresay that both their enemies and controllers (too varieties of the same thing, really) are not going to be happy with the result. I wonder what kind of flack Ron will get for leaving them and allowing them to go off to "who knows where" without control? I do hope he's severely chastised for that.
Hawaii offers a good place to train and plan and they clearly have access to the help they'll need. They really need a clandestine way of communicating with those they trust back in wizarding Britain and coordinating with them.