One cold take a look at xda.developers.forum that is a forum looking similar to what OP is suggesting.

You have you OS's with device subforums that got devided into 3-4 subforums and a general subforum for each OS also devided into 3-4 subforums.
It's pretty easy to navigate around that forum and find things for your device specific or something in general for your OS.
I really like XDA and the way it's build. It's a bit big and got 4 mil.+ users, but still git the 'home' feeling in your device section.

Regards Dousan...