I just started to read about this coin and have one question, what stops someone from setting his reward multiplier really really low to make sure he has a extreme amount of chance to be the winner and so is able to mess with the blockchain?
The lowest multiplier is x1. This is the same as BTC. You can't set the multiplier to a multiplier less than 1, thus you can't mess with the block chain. The difficulty of finding a block is the same or harder than BTC code.