Debate:Is infinite regression ever valid as a form of reasoning, or acceptable as a way the universe works, or came to be?

No. Infinite regression is a cop-out. It is closely akin to circular reasoning, except that the line of reasoning is not so much a circle as a spiral, into the infinite past or at least through an infinite number of prior steps. For example: How did life originate on earth? It didn't--it couldn't have. So where did it come from? Did God create it? No--no God-talk in scientific circles. (Francis H. Crick once wrote a nasty letter to Winston Churchill suggesting that a brothel would be just as appropriate as a chapel at Oxford University.) Therefore, life was deposited on earth from the outside. How? By a ballistic missile or a comet's tail. Where did that life come from? From another planet. But how did life arise on that other planet? It didn't--couldn't have--too much information. Did God create life on that other planet? Oh, no. Therefore life was deposited on that planet as well. Where did that life come from? From another ballistic missile. And so on, and so on, for an infinite number of steps.