I`d have them looked at by a herp vet to be safe, the snake may need a course of anti biotics. If when he sheds, it comes off nice and cleanly in one go, that`s a good sign. If it doesn`t, and clumps of skin stay attached right where the injuries are that would indicate a potential problem and can make the injury worse by collecting skin. A vet is the best person to talk to here. As for feeding it more often than it has previously been fed, how big is it? If it`s an adult snake, it only wants feeding every two weeks, snakes are very prone to getting fat in captivity so beware of feeding it all it wants. It should be round but not all puffy looking. You shouldn`t really be able to see the spine standing proud on it`s back. How`s about a photo, of the snake and it`s injuries. Switching from live to thawed isn`t something i`ve had to deal with but I`d imagine if any snake is going to be easy to switch it`ll be a Kingsnake ! lol Those guysget quite excited at the whiff of food. Maybe brain the food item if it won`t take it at first, they just can`t resist the smell of brains and blood..... Mmmmm yummy lol