1. I don't think this is a bug. I think it was done on purpose by Jelsoft.
2. Could be a bug. I haven't been able to test it yet. Perhaps this was also done on purpose. (you change the reply icon, not the topic icon)
3. I think it's supposed to be like that. Javascript probably doesn't make it possible to paste at the cursor.
4. A bug. I hope it will be fixed in the upcoming vB version.

You can't use vBcode in topic titles, luckily.