M.B.
I went without dairy for my second son and am now totally soy free, dairy free, egg free and gluten free. Rice milk or almond milk are excellent milk replacements. Cheese is the most difficult product to replace. The rice and almond milks are enriched with the calcium and vitamins that are in the cow's milk, so you're not missing any nutrients. Sprouts has some cheddar cheese slices that are rice based and do not have casein (dairy protein) or soy. (Note: you have to be very careful as some of the rice cheeses actually contain casein, which is the milk protein and the primary source of dairy reactions). It does definitely limit your ability to consume processed foods, but that as you mention that is far, far healthier. It also does limit or add additional restrictions to eating out as many restaurants add butter as part of the food preparation and there is always the issue of cross contamination, so you learn to be a very "picky" restaurant patron. You should not have to avoid soy oils, however, as those should not contain the protein, which is the allergenic component. You are also very lucky that with the new labeling laws that went into effect at the beginning of this year (or maybe last) that all products must spell out if they contain one of the top 8 allergens, which includes "milk" and "soy", so your label reading should not be too difficult. You may initially lose weight until you find replacements for your favorites, but I wouldn't count on it. There are some good books that you can find at the library or at the bookstores on preparing food without the allergens you mention, but that's really not necessary as you can replace the cow's milk in recipes one for one with the rice or almond milk. For baking, you can substitue vegetable oil for melted butter or a non-hydrogenated shortening or coconute oil for butter and get good results. Also, ghee is clarified butter and is casein free and should be okay to consume. It can be found at sprouts or Whole Foods and is wonderful for replacing the butter taste in prepared foods like toast, veggies, etc. It is quite expensive, so I wouldn't use it for baking. It is also a good source of butyrate, which is healthy for the GI tract.
I wish you well and I'd be happy to answer any specific questions you might have. I've been dealing with this for nearly 12 years.
M. B