You can already do this as far as I'm aware. Just go to the category and click 'Mark Forums Read' on the top menu. A pop-up will appear asking if you want to mark everything as read or just the category you are looking at.Perhaps the ability to mark all threads read in a specific forum category would solve the issue then?
As we had discussed earlier, the first request is really hard to do (and to do right). Let alone dedicating efforts to format a post in both templates, and then if we need to update a post... phew. On the other hand, your second request (open in new window) is super easy, so I'll get that done today.
News from the forum has the little one sentence and a link to the real front page post, that still doesn't pop a new tab (opens in same tab still).