Yes, when iOS 6 comes out it will be free of charge, just like iOS 5 and iOS 4 were.
iOS 6 is free.
You can get free apps without a computer for iOS 6 or 7, however you can not get paid apps for free.
Yes, Apple iOS 5 is free.
Some ios 6 devices can be jailbroken.
yes its free
yes its free
Probably not. The only OS for iPhone currently in beta is iOS 6. There are is no iOS 5.1.2 currently in beta and iOS 6 should be out within a few weeks. Unless a security hole in the current iPhone OS is found before 6 is released, don't expect an update to iOS 5.
Yes you can.
No. It is just to soon for the devs to get an untethered jailbreak for iOS 6. Plus iOS 6 isn't available to the public just yet.
Yes. All iPad minis should be running iOS 6 and can update to iOS 7 this fall.
At the moment iphone 6 runs ios 8.1.3
Yes. iOS 6 will continues to support voice memos just like iOS 4, 5, and 7.