Your symptoms cetainly sound like they could be some form of RA, the only way to find out is to see a Rheumatologist, then the Rheumy can run the appropriate tests for a diagnosis.
My AS started with hip and lower back pain and is now affecting my neck.
I do get swelling and tenderness in joints, like you mentioned, but I think that may be due to my Crohn's Disease.
I would make an appointment with a Rheumy and take your list of symptoms and concerns with you and keep pushing till you know whats wrong with you.
Good luck and let us know how you progress.
PS - your signature at the bottom appears to be more than 10 lines, do you think you could cut it back to ten - thanks Jo