I think that you are going through a lot of time and trouble for no reason. From what I have observed, counter rotating props only exist in the real world. And besides, the only reason for two engines is for when one engine quits the other takes you to the scene of the accident.

One other suggestion and that is as previously stated, do not lean one engine to match the RPM of the other. I personally would rather run both a little on the rich side while trying to MATCH rpm's. YES, I said MATCH rpm's. If you are to far off, you will be creating a yaw problem.