The judge has so far done a good job of not letting him force a mistrial. As for forcing counsel on him, I'm not familiar enough with Wisconsin law to know if that's possible. The judge said that WI does not allow for advisory or elbow counsel, so it seems like if he is going to go pro se he has to go it alone. At the federal level, the court can declare that a defendant is incompetent to represent himself if he is intentionally frustrating the process. But it doesn't appear that such a rule exists in WI, or I'm convinced that this judge would have already pulled that lever.
As far as an appeal, right now he doesn't have a leg to stand on. She was extremely thorough in the Feretta hearings. She made the risks perfectly clear, and she set very specific expectations for his behavior. Appeals courts tend to dislike arguments that boil down to "the judge should have let me do whatever I want regardless of the rules and the law."