Something to consider is that some states require to have a license to sell eggs. In my state I don't need one, if I sell to the publics directly. I will need one, if I sell to stores or restaurants. Crazy law.
Another thing to consider with allergy people is doing a skin test first. This test can not send someone into shock, because the amount is just to small. Simply beat the egg, and apply a drop to the forearm. Wait 5 minutes. Nothing, take a needle and scrape the skin a little bit (not to the point that it bleeds), wait 5 minutes. Usually after that you know, if you are reacting, and if not you are pretty much in the clear. Next would be to cook an egg and do a small taste test. Allergy people usually know how to test for food allergies safely. They can also take an egg to their allergy clinic and have them test them on them. At least that way they know that they are safe, and don't have to worry about a massively bad reaction. My husband is an allergy sufferer and now takes allergy shots. It works wonders on him. We are lucky and our insurance covers the shots, they are not cheap that is for sure.