These are pretty minor, just thought I would mention them. :)

1. My Inbox(x) link on the top-right keeps showing 3 messages even though I deleted the 3rd item in there, so only 2 are actually in the inbox, but the notification box does not reflect that nor does it track if items have been read (e.g. always displays a # despite the items being read/replied to).

2. The Forums widget on the home page does not keep accurate count of the # of replies.

These are for performance reasons, though I imagine we'll be changing the inbox to be more accurate soon.  The inbox counter is only updated when you log in at the moment.

Curse.com relies heavily on caching (as you can imagine) in order to survive patch day traffic and stay fully functional.

there are some heavy caching system, data should update somewhere in the time, no clue about the time required.

Sure enough, login/logout updated the inbox count, thanks!  Completely understand and would have done the same myself.  Thanks for the heads up! :)