Just a note: you are correct in stating that the magnets can potentially add to the damping in the system and slow the mini-bot down. However, this is not friction, unless you are rubbing the magnets or something else on the pole.
http://en.wikipedia.org/wiki/Eddy_currents
This is a very common high school physics class demonstration, taking a vertical aluminum tube and sliding a magnet down it towards the ground. It can take longer than one would expect.