1) C14 is assumed to be in equilibrium, otherwise C14 dating is invalid. Measurements contradict this assumption, yet it is used anyway.
This is a standard creationist talking point, and it is false.
C14 levels in the atmosphere are not assumed to be constant. It is known that they vary for a number of reasons. This was established by de Vries back in 1958.
And there is a method to correct for the atmospheric variations--calibration against tree rings and other annular phenomena. Not surprisingly, those various annular phenomena agree with one another to a high degree.
I've been reading the various creationist writings on C14 dating for years and 1) they don't agree with each other, 2) they don't match reality, and 3) they don't even rise to the level of junk science. They are merely religious apologetics, concocted by creationists trying to fudge whatever factors they need to make things come out they way their religious beliefs dictate.
3) Accelerated nuclear decay would affect all isotopes uniformly, "to the same degree" as you put it. I was not proposing an ad hoc acceleration of various isotopes.
Doubling the speed of radioactive decay would affect different isotopes differently. C14 would go from a half life of 5730 to 2685 years, while the various other half lives would still be in the millions to billions of years. To get a young earth, you would need a different decay rate for each isotope to make it all come out at 6,000 or whatever your favorite year is! And some of the side effects of decay accelerated to match a 6,000 year old earth would be spectacular!
Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
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