Avram, excellent points.
First off – The Torah’s Creation story implies that God’s work was intended for those on Earth. Does it prove that there is no intelligent life elsewhere? No, but I feel that it is implied. One can make other deductions as they see fit, but that is how I see it.
Second – All I said was “life as we know it,” referring to the common lifeforms of our environment. You are right about any other kinds of life.
Third – The moon’s gravity does indeed protect the Earth from incoming space debris, including asteroids. Just look at how many impact craters it has.