I think I was mistaken about the importance of the BSN to the Keep. The only Warden that shows up in the keep for me is my old one from 2010, which also happens to be the only one that appears on my BSN. I thought that if I could somehow fix my BSN stuff it might resolve my issues in the keep. I am going to keep on trying things but if all else fails I'll try the character creator.
My own opinion is that it's unlikely using the 2009 DAO character editor will help. What you describe, the "Profile not found" error message, is one you get while either trying to login to the Keep, no? Or perhaps I was mistaken and it shows after you've successfully logged in, since you say one of your Wardens shows up but not the others? I've never had the error, so I may have assumed wrongly.
Still, even if it's after a successful login to the Keep, it sounds like an issue with your Origin account and the "personas" associated with it. If you've made sure that you're logged into your account when playing DAO and DA2 (it needs to be the same one you're logging into the Keep with), as well as selected the options to upload the character data, then maybe one of the following solutions will help. Especially if the guides I hyperlinked earlier didn't.
Firstly, you could try following the steps in this solution, even if you're not using the developer console.
Next, make sure your EA/Origin/Dragon Age's account password doesn't have special characters (e.g. % or $) in it.
Thirdly and finally, and this is involved and might not be relevant if you're seeing one of your custom Wardens but not the others. You can go to this site and login using your Origin account's e-mail address and password. Scroll down to the section titled "Select a Default Persona", and select the one connected with Dragon Age. Then go to the Keep and try to login. See if it recognizes your profile. If not, log out of the Keep and repeat the process.
Good luck. I'm sorry you're having to deal with this problem. Sometimes, it takes a long time for the custom characters to upload to the servers and sync. I know mine did.
On the positive side, syncing old characters is simply about getting the headshot and name of your character into the Keep. It's rewarding, but purely aesthetic. For DAO and DA2, quest information is not synced with the Keep and has to be entered manually even if the heroes sync. In DAI, small spoiler, the game never references your Warden's or Hawke's first names and Hawke's appearance can be customized to look like the Hawke you want him or her to be (even if you never import a cuztomized Keep world state).