Good questions, I also wonder about the changing your username part, hopefully someone can answer that.
I have never flagged a thread yet (so I am not sure), but you may want to check your MyATS tab, which shows the threads that you create and/or comment
on (& maybe even threads that you have flagged, I am not sure), and it is at the top of the page after logging in; in between Recent Posts and
This content community relies on user-generated content from our member contributors. The opinions of our members are not those of site ownership who maintains strict editorial agnosticism and simply provides a collaborative venue for free expression.