I wish what you wrote in the second sentence were true, but it isn’t, at least not in my state, according to every lawyer I spoke with.
As for splitting the debt, there are a few exceptions to the rule, as you pointed out. Another exception is if the spouse went into debt spending money on adultery. It’s difficult to prove, though.
If they arent tossed out, prenups can address asset spilts in the event of adultery,as well as debt.