For rolling out of handstand, it's easier if you bend your arms when you roll, then later when you get good at it, you can practice it with arms straight and maybe with a couple of spots from your coach too. To get rid of the thump after your handstand from going over, stay hollow!
The roll is easier to do after falling over from handtand if you wait too long to come out of the handstand, like when you're really going over, like when you are trying to keep your handstand as long as possible. Otherwise, the handstand turn way is easy too, it's kind of like a cartwheel you know.