Assuming radio decay as an absolute dating method, without comparing to other known dating methods is not scientific.
You seem to have a view that radio decay is authoritative. When an animal lives, it ingests elements that have already particular ratios of decayed isotopes...thus giving it an “apparent” radio decay based date in excess of the fossil.
1) Why is radiometric dating not used for known recent (i.e. < ice age) fossils?
(see above)
2) What if the elements from which our universe were formed had an base amount of decay? i.e. they relative amounts of radioactive isotopes did NOT start at zero.
3) What if the rate of radioactive decay has not been static?
What matter is it if the earth is 3.5 or 5.0 Billion years or 5 Million years or 50,000 years or 5,000? Does it make the universe any different? No!
Does it imply the method of creation? No! So why you have your panties in a wad I don’t know.
As I said before, I have a BS and MS and 30+ hours of post masters science.
What education teaches you is that understanding and science are a process. When you get to the point where you cannot objectively consider alternative explanations, you have given up on science, and it’s become a religion.
But nobody has done that, so why do you make such a claim?
Anybody with even a cursory knowledge of these matters knows there are dozens of radio-metric materials -- from Carbon 14 for "recent" items (<60,000 years) out to billions of years with uranium-lead.
On top of those are other methods, from tree-rings to ice-cores, to geologic stratigraphy to comparisons of known fossil ages.
In addition, astronomical calculations provide us with ball-park estimates of the ages of stars (including our Sun), galaxies and, indeed, the entire Universe.
Point is: there are dozens and dozens of methods for estimating ancient ages, of which radiometric materials are very important, but not the only tools available.
And these methods all provide remarkably consistent, repeatable results.
BereanBrain: "1) Why is radiometric dating not used for known recent (i.e. < ice age) fossils?"
What are you talking about?
Carbon-14 dating can be used for any organic materials less than about 60,000 years old.
Tree ring dating goes back around 11,000 years, and Antarctic ice-cores to 800,000 years.
Of course, there are issues with every method, which must be carefully accounted for, but when results are consistent over a wide range of materials & dates, then as far as science itself is concerned, that's pretty conclusive.
BereanBrain: "2) What if the elements from which our universe were formed had an base amount of decay? i.e. they relative amounts of radioactive isotopes did NOT start at zero."
As a self-proclaimed "scientist", you have probably encountered something called the "standard model", of how the Universe was created from a "big bang" of pure energy, which rapidly expanded, cooled & condensed over billions of years.
In the very beginning, the tiny Universe was without form, and void of matter or even light.
Then from energy came first light, next the simplest of matter, originally only Hydrogen, and just enough gravity to clump them together into stars (and so the heavens were created, imagine that).
Now, stars come in all sizes and the larger they are, the shorter their "lives".
When very large stars burn up all their "fuel", they explode in a super-nova, in the process creating all of the heaver elements -- i.e. carbon, iron, gold, uranium, etc.
Some of these newly created elements are radiometric, and thus time can be measured from the moment of their creation.
But radiometric "clocks" are reset, whenever their material is melted and re-solidified.
Thus geological materials on Earth can be measured, for example, from the date of their melting in a volcanic eruption.
And the point, again, is: there are dozens and dozens of these methods, which have been used many thousands of times around the planet to provide us with consistent dating of various geological strata, going back billions of years.
That's what science is.
Of course, you don't have to believe a word of it, but whatever it is you do believe then, is not science.
BereanBrain: "3) What if the rate of radioactive decay has not been static?"
Then the answer is as simple as can be: there must be some serious scientific evidence of that, but there is none.
Of course, anybody might easily postulate that time itself fluctuates -- perhaps logarithmically -- such that what seems to our instruments a billion years was from a "God's eye" viewpoint really only one 24 hour day.
But there is no scientific evidence to support such hypothesis, and so it is dismissed, out of hand.
You, naturally, are entitled to believe what you wish, but if you believe that all of creation happened in "a day" or "a week", those beliefs are not scientific, regardless of how many diplomas hang on your walls.
BereanBrain: "What matter is it if the earth is 3.5 or 5.0 Billion years or 5 Million years or 50,000 years or 5,000? Does it make the universe any different? No!"
Now you are asking a specifically theological-philosophical question for which science itself has no answer.
That's because science is not designed or intended to answer such questions.
Science is far too limited in its scope for such questions.
It's why we have churches and other places of worship -- to answer those questions which science is way too small to address.
BereanBrain: "Does it imply the method of creation? No! So why you have your panties in a wad I don’t know."
What are you talking about? My undershorts are perfectly fine -- so why would you even enquire about them?
In my mind, the scientific "big bang theory" fits perfectly with Genesis Creation account, and so I never debate against various scientific ideas based on religious beliefs.
There is a name for my opinions: "theistic evolutionism".
You should study it. It is the official teaching of the vast majority of Christian denominations, including Roman Catholics, mainline Protestants and even some Eastern Orthodox theologians.
BereanBrain: "As I said before, I have a BS and MS and 30+ hours of post masters science."
But, if you are also a "young earth creationist" then you loathe and reject any part of science which you call "historical science" -- meaning inquiries into the creation and evolution of the Universe.
So I'll say again, you are entitled to loathe and reject whatever you wish, so long as you do not call your own beliefs "science". They're not.
BereanBrain: "What education teaches you is that understanding and science are a process.
When you get to the point where you cannot objectively consider alternative explanations, you have given up on science, and it’s become a religion."
Sorry, but your beliefs are religion, and "projecting" religion on science is a psychological malfunction. So, don't do it.
The truth of this matter is that any serious scientist considers all possibilities -- we used to call that "brain storming".
But after due consideration, a real scientist rejects those which don't make sense, or can't be supported by evidence, etc.
What ideas remain can then be proposed as hypotheses fit for further testing.
If they pass the tests, they may become theories, and that is just about as close to "truth" as science can ever get.
So what exactly is your problem with all that?