I've fixed the uploading script, so the ID/PIN error should not happen any longer.
It will work with existing characters, or at least it should. I've tested with my existing test character. I don't see that you've uploaded your character yet; you need to run the GHFCensus program, select your last save game and click on Upload. First though, make sure you equip the Census Log in the game and record your statistics.
it works perfectly for existing character, I forgot to save it after I updated my save. however I was going to fix my post, but Bethesda Forums keeps kicking me off so I couldn't update that last issue lol.
here's what I was going to say "nvm, it works! now all I have to do is worry about getting a picture and background set up for my character"