I have been reading conflicting information regarding fraud and wasteful dissipation of assets. I have read that in some cases it depends if there was intent. What if the intent is spite and revenge? How could that be proven?
Proving dissipation is difficult - but not impossible. It is a highly fact specific inquiry, and success in the field is something it is highly unlikely for a non attorney to accomplish. You should discuss your situation in detail with a local divorce lawyer.
Fraud, on the other hand, is not usually related to dissipation...and the term "fraud on the marriage" doesn't make a lot of sense.