Since he has such sensitivities, try your own homemade hoummus. the authentic hoummus sold at markets has tahini in it, which is sesame paste from ground sesame seeds.It is often manufactured in a facility that also makes other nut/peanut butters.
If you have a mini food processor/reg food processor or blender, combine garbanzo beans or white beans (or really any canned beans) that have been drained and rinsed. Add lemon, olive oil, garlic/garlic powder (go lightly so it doesn't upset his tummy, salt, cumin and a splash of tabasco (this will not add heat as much as another flavor layer. Whirl it up and keep in your fridge for about 5 days. Serve with bread for him since it sounds like pita chips may be too ambitious. With white beans, a little olive oil, lemon, red wine vinegar (little), garlic (little), salt/pepper and some basil/oregano make a yummy Italian bean dip. You can add cumin, garlic, lime, oregano, salt to red/black (or white?) beans for a mexican dip. Lentil soup/salad is another idea that is delicious. Peas can be pureed too with bread dipped in.
As he grows, try to introduce him to the whole pea or bean so that he can start getting used to chunkier food.
Beyond legumes/beans/etc., cooked ground meat (turkey, chicken, beef or a combination) is a great option simmered in tomato sauce (saute garlic cloves in olive oil til golden, add tomato puree, oregano, basil, little salt, pepper and then simmered for hour(s). This will be even better reheated and can easily be frozen in small portions for him.
Taco meat is another great option. The key is to get the ground meat broken down well.
Beef stew usually produces meat that falls apart and is delicious too.
As far as soy is concerned, it is just my opinion that the jury is still out on whether it is a health benefit or a risk to hormonal development (due to soy's phytoestrogens). They say that if it is fermented (miso, tofu) as opposed to just processed (ie soy milk, soy protein incereals, etc), fermented is fine. But personally, I still would avoid it since there is so much controversy.
Don't drive yourself nuts with the whole protein thing. Try to fit it in whenever you can with the balance of his meals, but if he is growing well and getting his vitamins somehow here and there, I think he will be fine. I would worry more about getting him past his 'texture' issue if possible. Once he can better tolerate appropriate sized "chunks" of food, the more options you will have to feed him.
P.S. A great thing to try are some dehydrated apple and pear slices in the snack food area of Costco. I was ranting about these earlier this week because they first feel crunchy but quickly 'melt' in your mouth. They were a great transition to finger foods for my daughter when she was 8/9 months old. She still loves them because they have such a sweet taste.
Good luck.