I'm not a balldriller, so I'll assume that some if not all of these explanations are correct.  It' seems counterintuitive though to place a pin 5 inches from the PAP to decrease rev rate for control and then try to dig a bit of core out of the ball to increase rev rate, when one could buy a ball with a 5" pin and place the pin 1.75 inches from the PAP giving the same amount of axis migration and also giving a very noticable increase in rev rate.

There are certain beliefs in ball motion that could easily fall into the irrelevant relevant category....static weights, pin up vs pin down, pearl vs solid...

Static weights is obviously a horse that has been beaten to glue...

Pin up vs pin down should be also looked at in a simplistic manner - if you place a pin directly below or just above the gripping holes is there a true difference? NO - if you place a pin 1" below or 1" above the gripping holes is there a difference...

I have to disagree with your assessment here. The majority of my equipment has always been drilled pin-up. A lot of my balls with the pin right over the middle finger. Here lately, I've been experimenting with pin-down layouts extensively, and for me, the pin-down layout is much more versatile, and useable on a variety of conditions.

I throw from 13.5- 15.5mph when bowling in most of my leagues. I have about a 350 rev rate, and am told that I have a lot of hand.

For me the pin-down drillings allow me to "hit it" or back-off as the condition  requires, and I find that I throw a lot fewer splits now than ever before. Now mind you, the heaviest condition I throw on in any of the 4 leagues that I bowl, is a medium condition.

So to say that the change from pin-up to pin-down is imperceptible is not true to me. But, as in all things bowling, it depends primarily on the operator and the conditions he/she plays on. If I were playing on a heavy oil condition, I am pretty sure it would be much harder to read whether there was any change whatsoever.

Did you replace the exact same balls that were pin up with pin downs? If you didn't you can't truly justify that statement
Trust me there is a lot to be said to what one thinks they see which if proper or correct to the eye increases one's ability to relax and perform...

Yes, I did. I previously had a pin-up Outlaw which I re-drilled to pin-down, and a pin-up Infinite Theory, re-drilled to pin-down. The Infinite is asymmetric and the Outlaw symmetric, I believe. Both of my new reactions are miles away from the original reactions I got from these balls. Both balls are much smoother, and break later. For me they are much more controllable.

My Outlaw is 30x 5 x 70.

My Infinite is 20x 4.5 x 70.

Previously I could not use my Infinite in any of the houses I currently bowl in. It would read the mids strongly and make a huge move off the spot! This has now changed. I can now use it in all my houses, and just align my feet, while changing releases for desired amount of hitting power.

Rev rate is solely and purely based upon the bowler and nothing else. You are referencing differing variables...RG is similar to an ice skater, if the ice skater's arm are closer to their body, they spin faster (low RG)...in the same sense, if the skater extends their arms, they slow their spin (high RG)...but the spin rate is still dependent on the ice skater's ability
Hook is any deviation from a straight line and predicated on more than merely the core dynamics and/or core numbers...for the core to have any effect on the reaction, the bowling ball has to slow down...this is (minus bowlers attributes) predicated by surface. If the bowlers ball speed is slower, the ball will tend to slow earlier and/or easier. If their ball speed is higher, the bowling ball, without proper amt of surface, will labor to slow down and struggle to change direction.
A bowler's ball speed dictates how the bowling ball will slow down...after that the rev rate, tilt & rotation dictate what the bowling ball will do at that point.
Bowling balls are merely tools of the bowler and should be used to compensate for what the bowlers lack and/or need in regards to reaction.
An object at rest remains at rest...no matter the RG or the diff until proper forces are applied plain & simple.

If you are under the assumption I am unaware of ball motion, ball reaction and/or what creates it...in abt 6 months (give or take) you can pick our next book in regards to this...thank you for thinking you are explaining, well not sure what you're trying to explain but you're off base in your assumptions...I am good in the world of physics and what is attributed to actually creating ball reaction.

One last thing, again rev rate is not predicated on a bowling ball or it's inherent core dynamics...it is solely based upon the bowler and their applied forces...bowling balls are tools or extensions of the bowler

which ball could you propel with a higher rev rate, a 10lb ball or a 16 lb ball, and why?

Wait, you mean I can't get a bowling ball that will make me Jason Belmonte?