I think as long as their vacumed sealled they should be okay frozen. It's the thawing process that can screw them up. Make sure to thaw in very icy water & you should be fine. I've try never to freeze my crustaceans unless absolutley necessary. Of course I work in South Boston,so I only get sea food if I'm making it that day (or weekend).
I thought all crab had to be kept alive, or cooked from a live state to save the meat? Otherwise they would release a poison that would ruin the meat. Only way I have ever had crab was frozen precooked. Of course I am from michigan and we don't have a lot of oceans near by lol. That being said I wouldn't hesitate to freeze it after you cook it.
the crab will freeze great for 3 months after that it starts to get a off flavor vacume sealing is a great way to freeze your crab you should try smoking some of the crab meat i did mine at 225 for 30 min in a heavy smoke it turned out great good luck i have trouble keeping crab around the house for a week let alone 3 months