I watched the first two YouTubes. His first mistake is to interpret every word of the Bible literally. He also implies that the scientific community hasn't progressed - or, in fact, tested or measured anything at all - since 1833. He's approaching his argument from the wrong direction - he has a result he's trying to justify, rather than using evidence to determine a result. That's backwards thinking, and always a bad idea.
Also, the moth could have been caught in a mudslide, the comets could be so large and the tail so small that the loss in matter is negligible, and Ussher was around in the 17th century, not the 16th.