I've got this place open while at other sites and I keep getting notification numbers that pop up in the tab, but when I come to this page I've got nothing. What gives? And where the PM button thingy located?

We are still working on adding private messaging so that's not here quite yet.

On the notifications, they represent new posts across the entire forum. So if you come to a specific interior page you might not see anything new. But if you head back over to the homepage when you see the badge, you will likely see some new posts within topics (or new topics).

Sometimes a quick refresh of the browser also gives me the new stuff.