The forward flight aerodynamics of the fuselage should possibly be designed to try and impart a CW roll to the craft to offset the CCW torque (looking forward) of the propeller.

Make the primary longitudinal strength of the fuselage consist of three composite beams. Two beams at the top sides and one centrally located at the bottom. At the cockpit the two upper beams will be located between the windshield and the door/side window. At the engine compartment, this arrangement will allow for three removable panels. One on each side for service and one at the top for removing the power train and engine.

These three 'beams' in conjunction with the panel between the cockpit and the engine compartment represent two tetrahedrons; for strength.

Consider venting the engines cooling air (or some of it) out between the T1 and T2 sides of the V-belts. This area may have limited outside flow because of the fuselage and blades restrictions. Locating the outlet here might reduce drag and the low pressure might help draw air past the engine (at least in forward flight). This might also allow the two horizontal slots to be reduced slightly.

The V-belts might be located within two aerodynamic tubes that support the sheave and shaft.