CD Key method still works - it is only purchases of E D made on Steam after April that need the new non-CD-Key method.
So duff excuse for making a whining quit thread.
I would suggest that the OP do the installation and verification of just the base game using their Steam CD-Key and then after checking that the base game runs OK, trying to find out how to add the Horizons that they bought from Steam recently - I think that might be a part of their issue (apart from their email address issues). Support will help there once the backlog from the holidays gets cleared.