I am also lazy, so I like to leave stuff that's already in ubb to ubb.
Not having my own box to edit a topictitle saves me the code to make sure the current subject is correct

1. It would be nice to be given an opportunity, via js popup or form, to enter a "new" name for the topic. This saves you from having to manually edit the first post, which lazy admins like me would really appreciate!

Alternative (less work and safer to code) would be to have a checkbox when you edit the first post of a topic with "Rename the rest also".
Heck, for our board a checkbox would not even be needed. We can force it always.