Tofu is so mildly flavored that if you're using anything like vanilla or just fruits it will overwhelm the tofu. If you're in Phase 1 and want to make a peanut butter smoothie, you'll definitely have no problem. Usually for drinks and dips you'd want to use silken tofu, soft or medium. It usually comes in aseptic boxes like juice boxes, and doesn't need refrigeration until it's opened. Handy!
Raw eggs aren't that bad in smoothies or milkshakes - they make them very thick and creamy. Make sure you're comfortable with the egg source, though - salmonella is not an approved diet plan, as far as I know!
Ciao!
Solarmama