I'm afraid this system strikes me as being a bit overly complex ... I don't particularly care myself

++ for that; same sentiments here.

If I were designing the system, I might go for one where only up votes were allowed, and there was no reward for voting -- what kind of democracy bribes people to vote

As has been stated in this thread somewhere, also in other threads, PerlMonks upkeep, policy and such are not about democracy.