I have wrtten alot of info relating to gut problems on curezone -- see here.
Yes, you guessed right, GERD and Low Stomach Acid problems can certainly be related or connected to hypothyroid and low thyroid conditions. That's why, in my own full protocol for this gastric acid problem -- explained here -- I include supplementing iodine to help cure it. Remember that 95% of all Americans are deficient in body iodine. Iodine is needed by both the thyroid and by the stomach to produce sufficient levels of gastric acid. The other minerals and vitamins listed are also essential.
Everyone, including doctors thinks that only the thyroid needs iodine. From the research that I've read, your body needs to maintain a daily store of 1500 mgs of iodine a day to be healthy. Your thyroid only needs to store 1.5 mgs iodine per day. That's right, iodine is needed for many other critical jobs in the body besides just helping the thyroid. Every single cell in the body needs iodine.
Hashimoto's may seem tough to cure but this condition is usually caused by both a lack of iodine in the diet as well as a lack of certain essential and critical minerals described here, here and here. There may also be excess heavy metals or halides(excessive bromine, fluorine in the body) issues contributing to your thyroid problems as well. I would investigate this website if you want some honest thyroid answers. A good research article on Hashimotos here. More iodine research from Optimox research here.