1. You can, but I think it sends out emails, and I'm not
entirely sure if it works, but it should. However, it wouldn't disable the new post indicators in other areas.
2. Yes, but it's not as sophisticated as on say, IPB or so. You have to use Quick Reply, and you have to use the 'quote' button for each(The one beside the reply button, not in the BBC menu.). It's complicated, but works good enough in the end, though it might take a second to load. One thing though; it doesn't work across pages, which I don't really like. =/
3. There's a setting in the look and layout preferences on your profile that can change that. =)