[squeeforever]

to answer your questions:
13. you will have to change the gearing from 12 cells to 14 cells but not much although i wouldnt go for two different gearings because once you find the right spot i wouldnt change it since it will cause something to be to hot or possible fry something.
14. no, but i would grind a falt spot on the shaft so it wont spin on come off.
15. i would go with the 5mm because i have seen broken shafts. also, i would get the strobe slipper setup because you will eventually want to or need to get it and it would be cheaper in the long run to just get it from the start because you will have to change from 32p to mod 1 and the pinions arent to cheap for 5mm.
16. no plug although you could use one from novak. most people make a mount and use the motor screw holes to mount it.
17. the 9920 is computer programable but doesnt have to be. the programming cable isnt required, though.