the notion of pushing a child to "do it right" in regards to drawing or having fun on a bike is being over-bearing. that is simply taking the fun and creativity out of an activity - as if they were doing something wrong in the first place. take a child development class - you obviously have little experience with raising children. a child does not care about "proper riding technique" - they just want to have fun on the bike, not be forced to be the next theo boss.

the reason why a fixed-gear drivetrain would be potentially dangerous is explained quite well by mihlbach. re-read what he posted and think about it this time.