I'll pick #2. The output window is visible before I do the commit. When I start the commit, I see a very fast flash of text in the output window, but it disappears before I can even see what's there.
Does SVN run multiple commands? Well, there are multiple things to do in a commit, so I would guess so, but the whole operation is atomic, so once any of them fail, it stops (and un-does anything that was successful). There should be only one error message.
Even when I do a successful commit, I don't see a "success" message, so I don't think the entire commit set function supports any kind of messaging - the flash I see in the output box is probably a fluke.