1st - that version of Rockbox is old as sin. (Almost exactly one year) You really want to upgrade to 3.0 if you want stability. Perhaps current builds if you want to be part of the hip crowd.
2nd - Yes, many (most) of the themes which worked then do not work now. Some (many?) have been updated to the new WPS syntax and can be found in the
wiki gallery.3rd - We can not, and thus do not support anything other than official builds installed with the official tools. I have no idea what is different about your version of Rockbox but it clearly isn't stock. Please petition the provider for support of this package if you do not wish to use official builds.
4th - We have an excellent manual which details the official install process.