Re: I dunno...
I don't know if you ever managed to get a reliable hitch on here, but I tow my Trophy with pretty much the same car. Mine is a 2002 though. I don't know how much my boat weighs, but it is a lot. I would say more than 3,000 lbs with the tower and the oversized fuel tanks, etc.
When I first started using it to tow, I had a little rigid inflatable boat. I made my own tow hitch and it worked perfectly. When I picked up my 19' center console though, I needed to rethink how the hitch attached to the unibody. As you mentioned, the sheet metal is pretty vulnerable, especially when you exposed it to any sheer force. I custom formed a bunch of .125" 304 SST plates to reinforce my unbody anywhere a fastener passes through. It was a pain but it works perfectly.
The one word of caution that I would give you would be to be carefull with the air suspenion. Never tow on 4 or 1, because you can damage the sensors which are upwards of 3,000 $ to fix.