I don't mean to be rude, but there is a lot of misinformation in this post. The aap has done some studies, and the conclusions were that it didn't matter when and in what order solids are introduced. I see what you are saying about the antibiotics, and I tend to agree with the leaky gut theory too, but I think a child would need to be predisposed genetically to developing the food allergy in the first place.
My sons allergies were apparent at 6 weeks old, he had no antibiotics, and was EBF until 6 months when I used the joneja allergy scale to slowly introduce solids. He is almost 5, and still allergic to everything, even thought I've eliminated most chemical and non natural ingredients from his diet.
Maybe some of those things contribute to food allergies, but I don't think, and research backs me up here, that they alone cause them.
OP, are you a member if kidswithfoodallergies.org? Great resource!