It's nice and all, and i realise that if you've chosen a strong password the odds of anybody bruteforcing this hash is very, very, very close to 0.

This being said, i'm always a bit sceptical if a newbie enters the forum with an account that can be thrown away in a heartbeat and offers a very big reward for about any task... IF somebody actually succeeds, and by doing so helps you improve your security, what's stopping you from just logging out never to return to bitcointalk using the same account?

If you offer a reward, it should be helt in escrow by a trusted forum member... At very least you should give proof of funds (altough this is not sufficient imho)