Yep, 55 lbs. of fish/seafood is the magic number per vehicle, NOT per person. However, it's not like they break out a scale and weigh it on the spot. I've come back with lots of sport-caught fish fillets for the freezer in a big cooler. Was is 40 lbs.? Was it 60 lbs.? I dunno... I think there's plenty of leniency as long as it is for personal use and doesn't appear to be a commercial enterprise or for resale.
Is the frozen shrimp cleaned or is it do it yourself?
It is exactly the same as the shrimp you buy at the Malacon, only frozen. They have everything from small to huge. Shrimp is available in large blocks, small shrink wrapped packages, or individual frozen shrimp by the pound.