I’m sorry but that’s just wrong. Sanford’s “genetic degeneration”(your words) arguments are presented to imply that purifying selection cannot maintain the genome against the onslaught of deleterious mutations. His point is clearly to show that life is unavoidably breaking down, not just that life didn’t evolve(and so life must be young). And you got the message, as you wrote:
Genetic Entropy results from the constant accumulation of mutations over generations, like rust in car. This mean that each generation will accumulate the same number of new mutations, which will translate to the same degree of fitness decline at each generation. IOW, fitness will decline at a rate proportional to its current value.
So according to Sanford’s genetic entropy, life can not have existed for billions of years as it would have gone extinct from genetic entropy long ago. That is his message. And you’ve given all appearances of agreeing with it up till now.