Thanks :)

For crap articles, people can vote them down, which will move them lower on the new articles tab and popular articles tab if they are voted low enough. Also, I can manually delete obviously crap articles, or close articles that don't fit the format.

For crap edits, they can be undone in the history tab of each article. I need to do a little work in making rollbacks easier though.

If I get a lot of traffic, I'll have to write some software to help identify malicious edits.