Achievement badges: Amazing idea, love collecting achievements, and i love toribash, Two great tastes that taste great together? They should be stackable though, so say if you beat an in game admin twice, you would then have 2 Anarchy badges
Merit Badges: not 100% sure of what you mean by this, do you mean like, if a TTM liked a set you made, they would award you one. or like if you won an event, you would be awarded with a PT trophy?
Collection items: To me are ok, I dont really need pointless items saying i like aikido, or gaia. But thats not saying that if they were implemented i wouldnt buy them