I think the random queue idea is actually a very good one, and should make the rating distribution a lot fairer.
However I agree that there should be a threshold (around 10-20 IMO) after which you can rate whatever game you want. I was surprised to find that this is not the case after rating 47 games. At this point, in all honestly, what remains in my queue is what I would rate quite low and I refrained from doing that and have stopped rating altogether.