Alfred, medical branch blocks are used to discover if cervical impingement is causing shoulder and arm pain.
These blocks can result in lasting pain relief. Otherwise the patient can return to the source of this pain with facet joint injections. Facet joint injections can result in lasting pain relief. Otherwise the patient can have the nerve ablated with radiofrequency.
Increasing cervical facet nerve impingement is probably sequelae from the other serious pathologies that you don't delineate in your post. Central canal stenosis poses the greatest risk for you. The Thursday MRI. Wish it were a standing MRI (few places perform them) but it will give you treatment direction. Cervical facet impingement is not likely to cause pain or numbness in lower extremities.
There is the possibility of long term "steroid flare" causing increasing (frightening) neck back and shoulder pain without indicating a further compression of the joint.
I am sorry you have that silly doctor, they slow you down.
I'd erase the comment that repeats much of this I wasn't finished and accidentally posted. Mostly I wish you luck. As you already know, there are remedies for you.