If I answered in a thread I like to sometimes just check that thread quickly, if there was any new activity. Now that this forum isn't overly active yet, thats possible with the "View new Posts" button. I fear (or better, hope) that will change in the future. In that case it would be harder to check your own threads. Thus I think it would be nice if there was also a button to check only the threads where I was last active. Something like a "View my recent posts". I'm not sure about the wording, though.

I'm getting notification emails from the threads i posted in, so i can keep track on the activity in those threads

Well, I'd prefer an overview here in the forum more than email notification...

In the user's control panel there are some listviews like "my last posts", "my last threads" - but that what would be great is: "answers in threads where I posted", isn't it?

Yes, Michael, that's a possibility. Do you mean by showing the posts themselves? Because I meant the threads (just like the "Show new posts" overview).

Riinse, the mail notification is nice, but it's not as easily accessible as a button on the front page. Also, if I'm already browsing the Forum, I don't want to switch to my mail to get the information!

You could also Bookmark your User CP -> Subscribed Threads. That has the advantage of showing new replies not only to your own threads, but also to threads you haven't replied to but chose to subscribe.