Unable to Save Files/Permissions Problem

Hello,

I had posted a previous problem earlier today (Re: Script errors in Safari/Unable to Save Files). However several problems are persisting. When attempting to load iTunes it says "The iTunes application could not be opened. An unknown error occurred (13014). I attempted to take a screen shot of this error and it says "Your screen shot can't be saved. You don't have permission to save files in the location where screen shots are stored. I went to try to download iTunes again to reinstall and it is telling me I do not have enough disc space - I have over 400gb free. Does anyone know what is going on? The previous fix was a keychain reset which appeared to resolve several problems going on in Safari.

Thank you,