Most moray eels with that shape can get to 5 or 6 inches high x 2-3 inches wide.
You should feed it a variety of foods including prawn/ shrimp, fish, squid and various other marine based meats. Buy some different foods from the bait section of a fishing store, or seafood section at a supermarket. Keep the food in the freezer and take a piece out each day, defrost it and feed it to the eel. Try to vary the diet so the ell doesn't become addicted to one food and go on a hunger strike if that food is no longer available. Varying the diet will also help prevent nutritional deficiencies.
Apparently they have poisonous saliva and bites usually get infected. Presumably they have some gross bacteria on their teeth and the bacteria get into the wound when you are bitten.
Keep using the feeding tongs for your own safety
Apparently they can reach 5 feet in length too, but most adults are about 3ft long.
Have good covers on the tank to stop them getting out.