What degree is your scoliosis?
The drs or the MRI should have that information.
Is it minor, moderate, severe, is there a rotation of the spine as well as the side to side curvature?

I don't know about the T3 problem, if it would cause problems or not, the MRI should show if anything there is affecting the nerves, which can affect the muscles too.

For the desk job & neck pain & spasms - You might want to read on our Thoracic outlet syndrome forum , there are lots of stretches, posture videos etc to help with those symptoms. lots of info in the sticky threads too.
http://neurotalk.psychcentral.com/forum24.html