You and your doctor know your case best. I would caution you against refusing surgery when you have venous/arterial involvement because of the risk of gangrene, stroke, and pulmonary embolism. However, the decision is ultimately yours. Make sure you have a surgeon who is really well-versed in Thoracic Outlet Decompression and your odds of having a really good outcome are high as you have a vascular form of TOS and a bony abnormality Those factors as well as not being in a lot of pain/medicated for pain prior to surgery and being younger are on your side.
I just had the surgery myself and though I'm not 100% yet at 7 1/2 weeks post op, my arm symptoms are all but gone. I still have a ways to go but my issues have been more centered around my post-op care than the actual surgery itself. I also have other medical issues that contribute to my symptomology.
I wish you the best of luck! And make sure you know what the risks are of refusing surgery. That is what ultimately pushed me to take this seriously as, at 25 and the mother of a 1 year old, I should make sure I stick around for awhile.