First off I want to be able to have a image of every computer that can be restored if there is a hardware change or something dies. This would be with win XP up to win 8. Can all the images of the computer be stored on a NAS that can be restored?
Yes: http://www.sevenforums.com/tutorials/67 ... overy.html
Keep in mind though, you may probably only do this via hardline unless you have a Wi-Fi extender or something.
I would also like the NAS to store all video (movies and Pics) that can be shared, video streaming, music streaming, from one central computer the NAS even over the internet. To any other computer on the network or that is connected to internet.
I don't believe a basic NAS can stream over the internet. You'll need to build a regular PC that acts as a NAS for that most likely. Could be wrong though.
One last question. Is there some type of hardware out that can let me access media that can let me see pics, movies etc from a NAS. To a TV, that has no computer attached. Maybe a roku with "play on" or other device.
If the NAS in question supports DLNA streaming services, then yes.