Allowing Users to Register Themselves and Post : Does WordPerss Handle these Problems?

You could call a function whenever a user publishes a post (checkout the publish_post action here)

In this function you would first check how many posts your user has already published, and only allow the new post to be published if this number is within a range you specify (ie. < 100)

Then you would check if the post content doesn’t contain any “bad words”, using strpos for example.

In any case, I would suggest that any large site where users can publish non-moderated content is a bad idea. Although you can make use of the community to sort out the mess, like the “flag” link here on stackexchange for example, which lets users report a “bad” post.