Q: Is it possible to change the thread title after you have made a thread? For example to add [SOLVED] to the front?
Q: When people say "...mark your topic as solved..." do they simply mean add [SOLVED] to the title; or is there a setting somewhere?
A: There is no longer a setting.
Q: Is it possible to change a thread's tags?
A: "Edit tags is at the bottom of thread just above the Quick Reply message box, on the right and below the Bookmarks line."