What motor-limit does this ESC have?
This ESC is designed to handle Tamiya super-stock motor, those motors are 23 turns.

Does this ESC have a BEC?
No, this ESC doesn't have a BEC. But that doesn't mean that you need a separate receiverpack, as you can plug in the red connector into the receiver. This way your receiver will get it's power directly from the ESC.

Does this ESC have a reverse?
Yes this ESC do have a reverse.