I have 2 little suggestion on the style.
When I started working with XenForo last week I didn't immidiadly notice that the menu tabs have additional items when mouseover the arrow. I think the buttons should show more clearly that there are sub-menu items.
I also think the last post cells on forumhome can use a style that stands out more.
Perhaps a bigger or bolder font and move the phrase "Latest:" to the node heading?