I would consider mounting the motor either on it's side or inverted. This will allow you to direct the exhaust somewhere other than the wing gap where it meets the fuse or the hatch cover. I found I did not need the hatch for the fuel tank. Mine slips out into the radio compartment just fine. This is a small plane so keep it light and it will reward you with a great flying model. I mixed flaps and ailerons and they are just about usless in my opinion.

Enjoy,

JEB