Wow, this is dumb. Well, all I can do is try this:

Erratic path behavior of the craft: Lag, it's everywhere. Can't do much about it, unless you have a very good internet connection. If you get this many times, someone with horrid connection might be making this complaint.

Travelling at speeds outside of the limits of the game: Show them some runs where you can achieve a very good lap time/time trial time. There are a LOT out in Youtube.

Random bursts of increased speeds - Turbos/Barrel Rolls. Game mechanic. Direct them to Hellfire's Wipeout Tutorial: https://www.youtube.com/watch?v=IxzY...1994E3331211F5

An impossible race time for *flash speed class* - Videos of even better race times can be found on Youtube. Not a whole lot, but there are some and can even be achieved/bettered.

Craft randomly gaining air and rolling - These are game mechanics. Again, Hellfire's tutorial on the game covers it, direct them there.

If you have the name of the person/player who sent this complaint, get it, write it down, and appeal against it because only a bad sport would make these complaints.