(1) Do I need a full-size Arduino unit, or can I get away with one of the smaller-board Arduinos?
(2) Given the countdown/count-up-to-infinity functions of the sketch required to run this, basic as they may be (countdown from ~100 hours for service interval, count up from 0 hours/miles for total hour meter, odometer, and tripometer), would running a SD/MicroSD shield and storing everything on an SD/MicroSD card be advisable, rather than rely on the onboard flash memory?
(3) What would be the easiest way to take the power the bike's charging system produces and get it down to 5VDC, and what is the maximum amperage @ 5VDC an Arduino can RELIABLY be exposed to before it starts to flame-broil itself?
(4) This can likely be very easily solved with rubber isolators, but how impact/shock/vibration-resistant are basic Arduino units? could they likely survive the vibrations from a 200-500cc single cylinder engine, either a 4 stroke or a 2 stroke, in a dual sport/dirt-flat-track-inspired bike?
(5) Is there anything in how I plan to execute my goals that anyone more experienced with Arduino might be able to streamline a bit? To my [VERY] un-educated (on this anyway) eye, it seems rather clunky, albeit functional, at least conceptually.