Yes, Puerto Rico is a United States Commonwealth, so a person born there is a natural born US citizen, so provided he meet the other requirements for President, a Puerto Rican born on the island or anywhere else in the U.S. could hold the office.
No. In modern cuisine other healthier fats and oils are used instead of pork back fat. You can, if you feel that you must, use canola, peanut or even olive oil.