These things are really high in monosodium glutamate (chemical number E621). to find out more google "vaporeon e621" or for more products in general that have sea salt flavoring search "sea salt e621"
oh absolutely! be aware that it is possible to get too much sodium from it (like salt), but otherwise it's totally safe. Google "E621 safe vore" for more info about it being safe to eat
you're right, it's about as bad for you as salt - but in high consumption MSG, since it contains sodium, can contribute to high blood pressure and hypertension. Google "E621 hyper" for more about that