The synoptic gospels describe three hours of darkness accompanying the crucifixion. As a solar eclipse is impossible at Passover (which occurs at full moon, whereas a solar eclipse happens only at new moon) this is only possible if the sun itself stopped shining, during which period there would have been no decay-retarding emissions from the sun at all, so obviously the decay rates of particles would have sped up in just such a way as to make young-earthers appear to be completely wrong.
It also caused the existence of intermediate forms, why not? Flood geology is so passe.
4) one of the main signals that these guys see is an annual variation. Annual variations can have any number of alternative explanations.
Yes. I read a story (which I would be grateful if anyone could track down for me, I've tried and failed) about a group of scientists in, I think, Germany, who thought they'd found an annual variation in the gravitational constant.
It turned out their university had a large coal cellar which was filled up at the start of every winter ...