Thanks! I wish I had written it myself! Actually, I'm not sure who wrote it...
1. Well, I'm not lactose intolerant myself, but I've heard a large part of it has to do with not having the right kinds of bacteria in the intestines. Then again, I don't know for sure. I know that natives in all those countries you mentioned have eaten dairy foods for many centuries without problems. Why they get lactose intolerence when they come to this country is up for debate I suppose. For example, there are many Afican cow herding tribes that eat nothing but milk and meat. That being said, dairy foods have only been eaten by humans for several thousand years, so it's possible that not all of us are genetically adapted to it yet.
2. Yes, it's true that vegetarians have fewer problems than most people on the SAD (Standard American Diet). Vegetarians eat vegetables, fruits, grains, dairy, and eggs. This is a healthy diet. Weston A. Price found many healthy traditional societies eating nothing but these foods, with little meat. For example, he found healthy Swiss groups that ate almost nothing but bread and cheese (with meat only once per week). However, he found that societies that DID eat meat were also very healthy too(even groups eating nothing else but meat, such as the Eskimos, etc). The only "sick" people he found (with bad teeth, poor bone structure, poor physical development, high incidence of disease, mental problems, etc) were people eating modern foods (sugar, white flour products, processed vegetable oils, canned foods, etc) and people who didn't eat enough animal foods, or too high a percentage of carbohydrates (eg. too much grains or sweet fruits.) All the native societies he found ate SOME animal foods, however. Supposedly he found the best health among people who ate an equal mix of vegetable and animal foods.
There's nothing bad with eating meat. If you have ethical concerns about it, then I can respect that, however it's a perfectly natural and healthy whole-food. Humans have been eating it for millions of years. Chimpanzees eat meat too. Many animals do. It's called the food chain. Those that don't eat lots of insects instead (which are nutritionaly similar) The only exception is herbivores that eat lots of grass and leaves, but they have special digestive systems for this purpose. Meat has the same nutritional composition as our own tissues, and is much higher in most vitamins and minerals than plant foods.