Buffalo LInk Station NAS box issues

I have completed all the steps to move my itunes folder to the NAS box, so I can share my music/video without having to have the Imac always turned on

However:

1. Folder Location: On the Imac, the ITunes the folder location keeps resetting back to the old default location on the Imac (/users ....)
2. Duplicates: I tried repeating all the steps to move the folder, hoping that that would fix the issue but all this did was to duplicate all the music files (with a "_1" suffix to the filename). I have 12gb of music, sorting out this mess willl take forever!Why isn't Itunes clever enough to recognise that when a file already exists in the new location it should not copy it? and certainly not create a duplicate record!!
3. Apple TV : The Buffalo link station has built in ITunes server software that I have activated. However our apple TV cannot detect the NAS server (it can detect the Imac and my PC).
4. Our playstion can see the NAS but, of course, can't play any of the files.

Any help would be appreciated