those are excellent questions and i share your concerns. i eat meat and i do worry about the parasite thing. you might also want to consider that many parasites get into the system from people's pets and animals not from what they eat.
on the paleo forum i posted an idea i had about an anti parasite marinade. read that thread for ideas if you want to. but the basic notion is marinading the meat in anti parasite herbs and veggies like pau d arco, clove, garlic etc and then eating the meat either paleo style (raw) or cooking it. your question is making me want to give this a try.
let me know if you try an anti parasite marinade and i will do the same.