[@Lekkuen]
When he is mind controlling another body, he basically leaves his own body inactive as he is spending 100% of his concentration controlling the body and keeping the subject's mind out of the body. Which would prove to be mentally draining if used over a long time and when he returns to his body would be pretty drained. Plus he doesn't know what goes on with his body while he controls the other body and loses all his telepathic powers as well. Besides that I don't know what else to limit.

-edit-
The maze thing, basically just stalls the subject's mind from fighting back for a moment becoming like a short suspicious black out moment. He can continually trap the subject's mind creating a bigger memory gap but has a greater chance for the subject's mind to break out rather than brute force. So he always has to make a precaution to reinforce the maze every so often or risk being rejected from the body