At first sight it seems a good idea to me but I dont think bitcoin payment is gonna happen and additional features on their profiles dont seem too motivating for me.
Why is this necessary? People shouldn't be encouraged with monetary rewards for this because it will just lead to abuse and is one more system to game. We already have an issue with merit abuse yet you want to further incentive it by monetising it? People will just give their merits away needlessly to hit their quota and win a prize, thus merit is likely just going to those that don't really deserve it.
I ran out of idea regarding on what incentive to give. But the main point is to give them an incentive as a form of recognition to them.