My blood work was borderline for years. It wasn't until I had a goiter develop that an endo decided to do a radiouptake scan.
I had symptoms too, but doctors wouldn't listen to me.

When the scan came back abnormal (the left lobe appeared partially dead and non-functional), then I was given the hormone replacement. By then my feet were numb and my carpal tunnel very severe, and my palms and soles were orange (a cardinal sign of hypo). It took almost a full year to recover and looking back the changes were gradual and borderline.

I don't think there is a direct link to hypo and RSD published clearly anywhere. Hypothyroidism can cause peripheral neuropathies however, in the feet and hands mostly due to compression of nerves by a mucoprotein the body makes and deposits there when hypo exists. My feet and hands improved about 90% with the proper levothyroxine dose after about a year. My orange skin is gone (this happens when betacarotene from veggies cannot be converted properly to Vit A in the liver, which is accomplished by thyroid hormone). Turning orange is a cardinal sign that the thyroid gland is not functioning.

I believe the Hashimoto's antibodies are in the blood all the time. Most Hashimoto's patients have severe hypo and some even vacillate up and down depending on the activity of the autoimmune factors and triggers. Many Hashimoto's also develop goiters, but not all.