Symptoms generated by worn joints (arthrosis) of C1-2 would be headaches, base of the skull pain, base of the skull grinding and clicking noises and some occasional radiation down to the mid neck.
If you have scoliosis, it would be expected that your shoulders would not “be even” in the mirror. The shoulders align with the ribs and if the ribs are assymetrical (as in the case with scoliosis), the shoulders would not be level.
It very well could be that you have arthrosis of the upper cervical vertebra but your symptoms could more likely be generated from the lower cervical vertebra. This might be a case for diagnostic facet blocks (see website).