Yes. Nobody serves raw crab.
No you will get a lump for a few days
Cooked.
Yes, the crab stick, as it is commonly known, is made from surimi, which is cured. Within the curing process this is all cooked.
They do not always come fully cooked. Sometimes they come fully alive, attached to the crab. The reason they are offered fully cooked is so that people who want to eat them don't have to cook them at home -- crab legs can be hard to cook if you don't have the right hardware.
No. But it will keep better if it is. This can kill any bacteria that may spread to other foods before the crab is cooked. If you are careful, either way works fine.
Crabs has protein. In every 100g of blue crab (canned, raw, or cooked), it has 18g protein. Highest protein number is with queen crab (cooked) with 24g protein per 100g.
Eel is typically smoked and cooked before being used in sushi. Salmon skin is usually cooked up as well. Crab usually means crab sticks, which are processed fish that is essentially cooked all the way through. Tomago, is a chicken egg omlette that is very good and completely cooked. And there are lots of vegetables that are used.
Most crabs are grey. They turn red when cooked. lol.
Crab meat is typically fully cooked in the canning process and should be safe for sushi.
typically no, but there are some cooked ingredients: the rice, always, and sometimes the fish. Unagi, BBQ eel is quite popular for example.
no that way there fresh when you cook and eat them