If you want a divorce the judge will not make you go the route of separation. Those can be converted to divorces after a year anyway. If you want a divorce you are entitled to one. Why be stuck tied to someone you don't want to be married to. His post-divorce financial situation is his problem, not yours.
In a divorce your marital assets will be divided equally. As for maintenance, that is up the court whether either party should receive it, in what amount and duration. So your wife could receive maintenance from you. Get yourself a lawyer as soon as possible. Good luck.
No. Once you waived maintenance in your divorce you are barred from requesting it. It is possible to seek relief from the judgment under sec. 806.07 of the Wisconsin Statutes on the grounds you were coerced but that is a very long shot.
If the communication between your son and his attorney is not good then you would want to request a new public defender. I think they do an excellent job for the most part but are often overworked. Still, if you lack faith in this attorney ask for a new one.