I do think that middle-of-the-screen text goes a little overboard sometimes, but I don't necessarily agree with all of your pictures up there.

For instance I think a confirmation dialog when you're trying to abandon a duty is probably a good thing.

That being said a confirmation dialog for doing things like opening doors is probably not a good thing. Why WOULDN'T I want to open the door?

My thing was always the QUEST ACCEPTED and QUEST COMPLETED thing. The very first time I saw that back in ARR's beta, the first thing I thought was "well THAT will never get annoying." Honestly though by this point I hardly even notice it when it happens. I've just gotten used to the idea that the UI has a ton of visual clutter and there's nothing I can do about it so I stopped paying any attention to the unimportant stuff.