In iOS, you must go into Settings>"Brightness and Wallpaper" and then toggle using the brightness slider.
P.S. You can toggle this with Siri in iOS 7.
iOS 6 is free.
Yes, when iOS 6 comes out it will be free of charge, just like iOS 5 and iOS 4 were.
Some ios 6 devices can be jailbroken.
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.
right now they do not have software for ios 6
No, the Apple ipod 1st generation hardware does not support ios 6.
You cannot. If you buy a new iPod or iPad or iPhone, it comes in iOS 4.3.3 and you have a choice to update to IOS 5 or not.