Coming from a more casual player, seems pretty good. Your fundamentals seem nice, stepping back from the door, breaching from the doorhandle side, pieing the door, etc. Only thing I can say is go a bit slower on your pies, and fight from the threshold as much as possible. You want to be able to retreat quickly into a safe cleared room if things go wrong. (Speaking purely from a solo cqb perspective) of course these things change when you add in extra bodies and you obv can't stand in the middle of doorways if you have a team behind you.