Q: How many fields of science have to be flawed for creationism to be valid?

"Actually none. All that would have to be done away with are methods that have proven flawed, such as you mentioned, radiometric dating. However, that doesn't throw out all work done in Nuclear Physics or concepts that work. Carbon dating also has to be thrown out because testing on material from Mt. St Helens erruption proved that new material can date old even when we know it's real age. However, to accept evolution you have to ignor many chemistry and biology scientists who keep asking for more time in order to make evolution probable. You also have to throw out everything we know about the linguistic evolution. Languages have historically become simpler since the beginning of recorded history. The more complex languages have died, and the languages still surviving are morphing to simpler and simpler versions. Language is in essence de-evolving over time. Are we to think the neanderthals spoke a highly complex tonal language which all of our many languages have evolved from? Evolution only happens in the real world as complex to simple. It doesn't happen the other way around. Therefore we could not have evolved from apes. Our ancestors had the most complex language."