I’ve already mentioned the “View new posts” and “mark forums read” buttons in a couple other threads.
I’ve found the “flag post/user” button is missing; so we can report spammers or bad posts.
A “Quote” button next to a user’s name or post would be helpful now that the threads have gone linear again.
This is all I can think of right now, if I have anything else to add, I know where to look now