Most third party developers won't be looking in the pre-sales forums. I would recommend purchasing a licence and posting in the Custom Service/Development Requests forum.
Good luck.
I really don't understand where you are coming from. Yes, people are still running 5.2 which could have security risks etc, but XenForo works fine on 5.2 -5.6, why do you care what version of ZF XF is using? What benefit is so great that the current version cannot do?
I would imagine it wont be done in 1.2, I would assume it's a relatively big change and could have impact on stability. I would imagine it'll come in 1.3 or later.
If you are watching a forum such as "Resolved bugs" and there is a thread that is moved into that forum. Will you get a notification?
I guess the same could be said about posts (with merging etc).