1/2) If you're going with NiCad Battlepacks instead, then I would recommend either S28-400 MagMotors (more power but less thermal energy) or C40-300 MagMotors (bit less power but more thermal energy so they'll last longer), and I'd recommend running the S28s on 24v/C40s on 36v, and using at least 5 or 6 Battlepacks for either.

3) Okay.

4) Seems doable to me, although other people might question it.

5) It's okay, I have made stats late before and have had to change them for it. :P

6/7) Yep, it's all good. For a paint pic that was actually a pretty good attempt, although if you feel up to it, you may want to try your hand at 3d-modelling programs such as Rhino or SolidWorks (Rhino is a bit easier to use) to give an even better visualization.