Are there things that creationist can't explain?

I mean what are creationists' explanation for Toba supereruption and impact craters here in earth? If humans coexisted with dinosaur, how did humans survive without being harmed by dinosaurs? Wouldn't there be an ecological collapse if during the first week of creation everyone was vegetarian? They claim that science does not explain everything. Correct me if I am wrong but if humans descended from Adam and Eve (and they are the only humans during those times. The bible does not tell that there are other humans that were created.) and if their children breed among themselves, then, shouldn't there be some genetic diseases that will be passed on to the human race and human genes does not show any variability?