"And why would the rules governing where life can come forth apply? Who or what enforces the laws of physics?"
I don't know why the laws of physics exist. I don't know why the universe exists. But I do know the consequences of some of the laws. One of them being that life forms do not appear out of nowhere, they are always created through a chemical reaction we call reproduction. One of the first organisms most likely arose from pure chemistry, and eventually life developed which could reproduce on its own, a self-replicating chemistry experiment, given the right amount of heat, pressure, chemical components etc.
"I don't know why the laws of physics exist. I don't know why the universe exists."
Stop there and ask yourself: "If I don't know this, how can I claim to 'know' anything?"
You "know" the consequences of certain laws, yet you have not observed life coming forth from simple compounds. How do you "know" what you say it true then?