Hi Drewster,
WELCOME!!
I really should keep my mouth shut, since I am just an imposter here (I am not officially diagnosed with anything, and my pain is 'all in my head'

) but to me:
fusion = ankylosing
severe neck pain and stifness = spondylitis
And there you have it....... **drumroll**......
"The Magical Ankylosing Spondylitis!"I believe that both the heel spurs and the carpal tunnel syndrome could be related to AS. I also know that heart conditions can develope as a complementary gift when one does have AS, but I am not sure exactly what that implicates.
My GP took a simple blood test and looked for the HLA-B27 (and I flunked...

), but of course a rheumy could do it too.
You should definetly check out with a rheumatologist. I am surprised you have not been shipped to one already!
See you later,
Jade