you shouldn't need to chmod 777 the files, in fact you shouldn't, for security reasons. If you've logged in as root, then you should have full rwx permission for everything.
If you want to grant another user root permission, look into sudo.
I'm not sure why you can't save files, I've never seen that error before. Does it happen all of the time, or just with one specific file? Try creating a dummy file under /root called dummy, with some text using some text editor, and see if that'll work. Then get back to us