According to Kashrut, enzymes are considered mere secretion and thereby all cheeses are Kosher, irrespective of the sources of the enzymes, even though they may be from non-Kosher animals.
It is my understanding that this used to be true; however, most Orthodox and some conservative Jews do not consider cheese to be kosher unless it comes from a kosher animal and contains kashrut certification.
Then, somebody else posted that to be strictly Kosher, you would have to have two kitchens - one for dairy products, another for meats. And that you cannot eat dairy products after eating meat products for four hours. I believe they said that you can eat meat after dairy food immediately, but not both at the same time.
It depends upon the region you are from. Usually Jews will not eat meat and cheese without waiting anywhere from 1 to 3 hours. And yes, to be strictly Kosher, you do have to have two kitchens--one for dairy and another for meat.
I am happy to be a reform Jew and so the dietary rules do not apply to me. Although I don't eat pork, I stopped eating it years before my conversion.