Top:
Announcements: ~daily
AL: Finished, so now rarely
Quests: Rarely, merge with Voting and Challenges
Voting: Rarely see above
Calendar: Never, already in PC, so remove
Challenges: Outdated and should be merged with Quests
Restrictions: Rarely, maybe only in bottom menu?
Court: Hasn't been used in years, remove
Intro: Please remove, contains really bad English so will only scare players away
Known issues: Never, somewhat outdated, but might still be nice
Forum: Often
Art: Never
Search: Never, seems broken
Free Credits, regularly
Right:
All at least occasionally except AL (as it's no longer updated)
I'd suggest merging the top lists; they're rarely used so don't need to take up half the menu
WP reward page could probably also be moved to the WP page as it isn't something you do so often you need it one click away at any time.
Bottom:
Don't think I've ever used one, Most seem like they should be there, though.
Documentation:
The Q&A on the LHO page took me 5 years to find. For the more info buttons you'd need to ask a new player for their oppinion as I'm having a hard time judging what's usefull myself.
Others:
I'd love a link to the Wikia somewhere, probably next to the forum ^^