Yes it does suck. The fish farm license specifically calls out which species of fish that I can stock. It goes on to explain that I cannot stock any other species of fish besides what is listed (unless I like fines). This is the newest 5 year license I just received. Maybe this is the new way they are doing licenses?
Crawfish is a good idea. I think there is already some in there, but I should help to boost the numbers with structure. There is also plenty of frogs in the spring, that should help also.