Hey LawnDart - a few comments from my kit-build and flying for the past two years:

Balsa cowl: Go for it. I laid my OS 70FS to the side and built a cowl around it and it looks great.
Tail dragger: Go for it. I put my mains in the wing ahead of the spar and tilted them forward (wheels right under the wing LE).
Wheel pants: Go for it. I didn't, but I bet they'll look great.
Dual aileron servos: Maybe. I originally had a single servo per the plans and it worked well. I converted to two separate servos in the center of the wing with flaperons, etc. and I'm a little happier with it, but I'm not jumping up and down about it.
Pull-pull rudder: What's the use? It has such a small rudder (it's not a 3D plane) that any old setup will do. I made my rudder 1/2 inch bigger and the stock push-pull system is plenty enough for that. Exreme throws barely hold it level in knife-edge flight.
Flaperons: See "Dual ailerons servos" above.

My suggestions:
1. Replace the ailerons torque rods with real 1/8" ones and glue them well into the ailerons - you'll never have the flutter problems I read about, even with one aileron servo - mine took many high-speed dives in stride.
2. If you'll put a heavy engine like my OS70FS on it, put the battery way back in the fuselage - just ahead of the tail surfaces so you don't have to use lead. I'll have to cut my covering away if I need to replace my battery, but it keeps the airplane light.
3. I Knocked half the dihedral off - it doesn't need it - it's not a trainer. You could even shorten each wing one rib bay and lessen its floating tendencies at landing speeds.
4. Mine came in at 5.5 lbs - lighter than the GP Ultra Sport I was flying at the time, and it showed.

Other observations:
- This plane has a thin wing - mine flies way fast WFO with an OS70FS and any prop I try (I've used APC 13x6, 14x5, 14x4).
- Keep the landing speed up. It'll come in pretty fast and float quite a ways, but if it gets a little too slow, it'll drop to the ground real quick. Fly it in to touchdown.
Enjoy it - it's much more pleasurable to fly than my Ultra Sport was and tracks like a dart. I think you'll really like it.

Hope this diatribe helps.

==Mike==