Hii salsa,
sounds like ye're on the right track re:the cx-spine. I'm assuming that your getting the joints of the neck mobilised along with the dry needling? Releasing the muscles should allow for easier mobs to the spine.
The 1st rib on the same side may be elevated causing more restrictions to that side of the neck, this should be checked along with spinal restrictions to mobilization.

From my experience Subscap will generally refer to the wrist, a "watch-strap" area across the joint. Infaspinatus may be a more likely cause of the referral to the fingers- If indeed it is as a result of referral from the R.C. Tight Infra will be shown on internal rotation of the shoulder. Physical Examination of the Shoulder — The Nicholas Institute of Sports Medicine and Athletic Trauma this shows internal rotn @ 90degs abduction (out to the side) If theres a big difference side to side this needs to be addressed.

Improving scap stability Has a few effects, An improved allignment of the thoracic (and lumbar) area will have a beneficial effect on the neck, relieving pressure on the joints and decreasing tension in the musculature of the neck, stretching the pecs helps this. Also improved scap positioning wil allow the R.C and scap stabilising muscles to function at an improved length reducing the stress on them.

Continue with the foam roller, try the exercises on the first page of this PDF http://beauchamphouse.co.uk/download/thorax.pdf, general extension, rotation and side bending using the chair to stabilise your lower spine - check with your physio so they can make sure your doing them right. Make sure to take a break, even for 30-60 seconds every 20-30 mins at the computer, do a little stretch/rotation and get your shoulders and neck back into position, this will help prevent the scap stabilisers from becoming overloaded.

It's hard to say where your pain is coming from without assessing you but improving your posture, addressing muscle tightness and weaknesses etc will always help. Any restriction to the nerve can and should be measured by your physio through a thorough nerual assessment which along with your own feelings about progress/pain/pains and needles will show any progress.

All the best