Basically I have some people who have signed up to post on one of my blogs but their posts have to be published by me and I'd like their posts to automatically be published but I do not want to give them full admin powers. I have them all on Contributor, will moving them into the 'Editor' category solve this problem? Also, is it possible to edit the names of these categories?
In your WP admin, you have SETTINGS > DISCUSSION options that allow you to manage who and when people can comment. Play around with those until you hit a combination that fits your needs.