You are correct sir...
I can NOT play any of my games from my old email address. There is a way to transfer games from one account to another but you need to do it before you link the email addresses. Unfortunately I found this after I transfered the email account to my new one.
"Have products on multiple accounts and need to transfer registrations? Click Here"
I have emailed Stardock at sales@stardock.com but have got no reply yet.
Not sure if this is the correct area in the forums to post this message. Hoping to hear from someone soon!