Erin, I see TF as the appropriate way to prepare each type of food (or which types of foods to choose/avoid) but among the zillions of foods out there, I can/should choose the foods that work for me/us. I started our transition to TF when we started gfcf, so although many people are very dairy-centric when eating TF/Price-like, that wasn't a good choice for us, but other things have been great. I particularly like the focus on foods that are easily digested, fermented veggies and homemade stock, and I like Price's focus on fat-soluble vitamins and more minerals. But the detox discussion is beyond even that, though I think that is a helpful change to start with. There are so many layers of changes that can and probably should be made with diet. And it's okay if it takes a long time--I'm, yet again, re-thinking what we're eating and what would work better for us, and I think I'll need to make more changes later on.
re: dark circles, my understanding is that it's a nutritional deficiency, but not any one specific nutrient. For some folks, just removing allergens relieves a stress on the body and then the nutrients you're consuming are enough, I know for my daughter, when her poop gets worse, her dark circles become more pronounced (though they got a lot better when we eliminated gluten), so it's a work in progress for us. And for my dark circles, well, progress is slower. The kids are easier, it seems.