Ability to disable core pages
I think the correct term for pages is routes?
I set my homepage to /recent/ and have removed the /categories/ icon from my navigation menu. So in my case, the /categories/ page is now pretty much unused unless someone visits the URL directly.
It would be useful if you could provide settings in the admin area to disable pages. So for example, if I disabled /categories/ then visited that page directly in a browser I would get a 404. The same would go for /recent/ and /popular/ etc if I chose to disable them.
This isn't exactly a killer "feature" but would help to keep a tidy site, focusing users on certain forum areas only.