I used to get my lashes tinted for years and loved it. I have Sjogren's Syndrome also, which is extreme dry eye. The tint used is very safe as it's a vegetable dye. No way would anyone be using a dye that is similar to hair dye on your lashes or you would go blind. You do have to be careful to get some one who does a good and careful job and to remember to keep your eyes closed when the tint is on. They usually put toner soaked cotton pads on your eyes, while the tint is on, to keep your eyes shut and to sooth your eyes. I never had any burning or any weirdness with the procedure. I would still be getting them done except the nanny state that I live in has outlawed it's use because a dopey woman decided to read a book while the tint was on her lashes and some got into her eye and caused a problem for her. She got a lot of it in her eye. This is why you follow instructions so now the rest of us have to suffer because of some dumby who didn't follow instructions.
You say you have sensitive eyes. Mine are about as sensitive as they get and right now I am suffering with eye problems due to the mold count outside. I look like a red eyed hell hound!
I used tint by a licensed professional for years and never had any issues with it. As you also have problems with soy, I would advise you to read the ingredients to make sure there is no soy based ingredients. It's possible. Doing a test patch won't work because the skin around your eyes and the lids are far more sensitive than the skin on your arm. Just check the ingredients and get someone who is good at what they do. If you do decide to do it, I think you will love it. I did and now must travel an hour into another state if I want it done. The woman who did mine would not do any tinting on me during allergy season, when my eyes were bothered. She was extremely careful, which I am thankful for.
Good luck and let me know what you decide!