1. Not at this time no.
2. At this scale, no there's no noticable differences between the bodies
3. For suspension?...Tires, stabilizer bars (or springs instead) and a stronger steering magnet (like a natural magnet) are a few things you can think about
4. Run the motor for several battery charges with no resistence (like upside down or with none of the gears on)
...And be sure to check out the Bit FAQ too!
