Yes, its impossible to look at every post, even briefly. And the curation thing, IDK... Whats quality and what isn't is a very subjective thing. Being too strikt will scare many people away and will take some of the fun factor of it all.
To the voting power thing... it might be worth concidering a equal power for all system, with a vote limit per day or something. The way it is now, is incredibly complicated. But I guess such a suggestion would meet a lot of resistance.