You can turn off the Post Preview by hacking a file or two – see http://wordpress.org/support/topic/53685. There isn’t a plugin to disable it (nor is there likely to be one, I don’t see any obvious way for a plugin to edit code) and as far as I know the uploads can’t be disabled unfortunately, and I don’t know which user levels get access to it either – like phpBB, WP 2.0 uses a ‘role’-based permission system, but unlikely phpBB, WordPress doesn’t actually tell you what each role does.
Anyone wanting to disable uploads – you can do this using the Role Manager plugin from http://redalt.com/wiki/Role+Manager
I think this should be a defaul option though, that’s editable from the Writing preferences. Same for Post Preview.
I happened to run into this page five minutes ago:
Kill Preview Plugin
http://redalt.com/wiki/Kill+Preview+Plugin
No more need to hack your WP files. 🙂
Nice. Ta for the link. Should speed things up considerably (wish I had it yesterday when I was copy & pasting in 30 new pages of text!)