911, You happen to be listening to a WM Super Chipmunk "expert". I've owned three and still have one (dont ask) and most of the things you mentioned are potential problems, looks like you been doing your homework.

Lets see where can I start. First off forget about the tail wheel. I always used the stock one and it never gave me probs. Just trim out rudder where you want it (flying) and then to make plane track straight on the ground just grab with vise grips (near swivel point) and bend it the way you want plane to go.

1. I'm not sure about what kind of covering but MonoCoat Missile Red and Signal Blue matches perfect. High heat ok.
2. Forget about firewall markings. With cowl on plane, engine shaft must line up with hole in front! Duh... Simple huh?
3. Fuel tank ok for Saito .91 and OS .91 Surpass.
4. I had so much trouble with retracts, I bolted a "dural" type landing gear to bottom on fuse (after re-inforcing it). No more bent landing gears! Do a search. I described it in-depth somewhere on RCU. You might want to do that anyway. Another problem you havent noticed yet is flemsey control rods.
5. The nose over problems will be corrected if you up-grade to (4.) above. If you keep re-tracts, the problems is caused by all the down trim the plane needs to make it fly level. Just get use to applying up-elevator when taxing (you should do that anyway)

Anything other questions about WM SC ask away!