That button at the top right is a bit of a teaser I guess. Just like I thought though, it just adds the forum to your control panel and if you go there right away and have just a few forums you are tracking it makes it easier than sifting through 20 ...
With regard to email notifications if using the post reply button, you should only get one email and there could be multiple replies, you won't get another email until you go back to that thread again. Here are the words you get in the email notification ...
"There may be other replies also, but you will not receive any more notifications until you visit the board again"
With regard to quick reply, like I said earlier, it is an add on to the original software. So a software guru on Reef Central may have been able to figure out how to also make it do an email notification. I can check into that one further.