[Ion]

The issue wit requiring a post count, esp one that high, is that it will cause many "that's cool, I agree" type of posts.

And if they do indeed make those kinds of posts, you can ban them. There should be something such as a "Trial" usergroup, and if you break any rules or make bad posts, you'll be banned. You'll move to the "Member" usergroup after 100 posts, and the staff members will make sure that the Trial members are making useful posts.