I was wondering does active subscription is required for posting questions on answer hub?
No, you dont need one
then whats the difference between forums and answer hub?
In my opinion:
On the answerhub you post bugs/crashes.
Forum -> longer discussions, in my opinion more people use it, WIP, personal discussions
I believe you can ask questions here on the forums (obviously), however the answerhub is…well the hub of everything. Bugs, crashes, questions, fixes and the like. But yes, the forums are generally used for other long-term discussions, or shennanigans.