The possible variations in the fine structure constant, Alpha, are not the panacea you seem to think they are. The variations in beta decay that the 1:1,000,000 change measured would produce fall a little short of the magnitude needed to save a young earth theory.
Humphrey's theory still has a few hurdles to clear before even making it to the status of decent SF, never mind science.
One under-reported problem is with having a 2 light year diameter sphere of water as the starting condition.
The current physical theories postulate a starting condition after the big Bang of almost pure hydrogen with some deuterium, tritium and helium. Stars formed from this, and generated the heavier elements. however, much of the hydrogen remains unused to this day, and hydrogen is by far the most common element in the universe, with the other elements being distributed roughtly as predicted.
In Humphrey's model, the starting conditions are 2 parts hydrogen to 1 part oxygen. This would produce a drastically different set of early stars, and a radically different profile of elements. Additionally, there should still be massive quantities of oxygen in interstellar space, both as O(-) ions, O2 and O3 molecules, and water.
Guess what - we don't see that.
As for the Helium argument, helium is an end result of a lot of decay processes.Surely if decay were proceeding faster than predicted, we should see more in the air, rather than less.
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