With regard to your third question about using pig enzymes in medicine, Sheikh Kutty, answers:
There are two different views regarding this issue. Some scholars maintain that it is haram on the basis of the prohibition of eating pig. Others hold that it is halal for two reasons: first, that what the Quran prohibits concerning pig is its meat and using the other parts of the body like hair and the like are permissible. Second, that in making such substances the pig enzymes have gone through different chemical changes so that the end product is a new substance with properties quite different from the original one. That is known in fiqh (the science of Islamic jurisprudence) as the principle of Istihalah. Based on the new properties which are completely different from the original one, there is no reason to prohibit it.
I personally agree with the last view especially when there is no way to get an alternative medicine that does not have pig enzymes. If there is an alternative medicine, then it is better to go for it and not for the one that has pig enzymes.