Really it boils down to whether you believe the laws of physics we observe now have been constant throughout time. If you do you’re called an evolutionist, if you don’t you’re called a creationist. Neither side has any proof, nor is any proof fundamentally possible.
The point being is, creationists have zero idea why they think 6,000 is some magic number in this case, other than bob said so in a book. But yea, books are written by men and men are liars. Even looking at things like RNA/DNA mutation rates in known species it's pretty damned easy to see that things have been around a whole lot longer than 6k years.
Again, please understand the underlying assumptions you are making when you concoct statements like this. Namely: DNA/RNA started as a single form and has mutated at a constant rate since then. You have no evidence to support that, and I disagree with every component of it.
Also, any guesses on why the 'modern' age is suddenly going in slow motion. Not exactly sure how you're going to pull that off without breaking chemistry completely.
And I'm not sure why you think the almighty creator of the universe would have trouble making chemistry... "work".