I guess the answer would depend whether, in your context , the changes are reversible or not. If they are, the changes will be between (not among, as there are more than 2 states). If they aren't, then it will change into. "What are three

It depends on the meaning you want to convey. If you want to say that you are moving from some sort of a mutual society, then you say demutualize. However, if you want to say that you move to a company, you may use incorporate.

The sentence is correct. However, it sounds strange - How about about?. Also you would want to use it when asking someone, in a potentially rude way, to finally give their opinion instead of doing something else - for example talking about

Perhaps you may put commas around finally if you want to emphasise that your dog has FINALLY come home.