Topic: 5 suggestions
1. Coloured topic subjects: give the user an option to select a colour (the color menu should have a description box so people know what the colour means) for the subject of his message. This would be specially useful if you don't want to have subforums per category, just one forum with subjects displayed with different colours suggesting the possible content of the posts.
2. Guests can post: I run a forum that's 99% about help. People basically post to ask for help when the official documentation fails. It turns out many people just have one question and no plans of staying after getting help. Letting them post as guests would save us bandwidth, not to mention the database would be easier to mantain without that many abandoned accounts.
3. "Enter a valid e-mail address" during registration should be optional when "Verify registrations" is disabled and the user should be informed about this.
4. User should be informed about allowed/disallowed characters for name and password when registering an account.
5. Rise the password length to at least 32 chacaters.
Thanks