After tinkering with the templates a bit more, I've fixed that. Now the posts have numbers, but the members' postcounts don't show on the threads.
I agree with Heald about discouraging low quality posts made solely for the purpose of raising postcounts.
In any case, this is an experiment. I think we can keep it this way for a week or two, and see how things turn out.
Oh, as for Ayeun's question, I think the pokeballs are an important part of the board's look and feel. That is, the forums wouldn't look nor feel the same way without them. So those who like keeping track of their postcounts and watching how new pokeballs appear under their usernames will still have that even while the postcounts themselves are hidden. Not completely hidden, though. You can still find them if you want to, they're just not displayed on the posts.