Could the US take out North Korea's missiles before launch?

Yes, maybe...but what about the 10K+ artillery tubes? Seoul is a small town of 10 million people, 22 miles from the border. I think nK could get off some tubes of Arty. Most of that arty is in caves can comes out on rails.

100%, unlikely. Most, likely. A couple ballistic missile boats and backup destroyers, poof they are gone. The risk is, so may Seoul.