A great read by the OP! Thanks for that!
I would love to have a nickel for each PM I receive from new M305 owners wanting to build tack drivers out of the factory rigs.

There is a reason I limit what we can do on the FIRST day of my M14 clinic(s). And that is tighten up things to significantly improve the overall fit with MINIMAL $$$ outlay. It's designed that way, to try and keep as much money in your pocket as I can.
Once we get to the rebarreling (more serious $$ outlay) and glass bedding (more effort outlay) with some new stock (potentially more $$) acquisition; then the costs might (big MIGHT) justify the increases in precision. yuk yuk yuk
So final question... what does Tactical teacher shoot when he has a chance to choose from the many, many M14 platforms? Just ask my wife: I only own ONE Norinco with a Citadel .308 barrel and USGI parts. And it's parked in a rescued USGI glass stock.
All my serious .308 work goes to my Accuracy International AX .308 with a Schmiddy PMII, ha ha ha ha ha ha
Okay, seriously now, that's my sponsored rifle. So that's not fair to mislead all of you, but I just could not resist! Yer dicks are still safe. ha ha ha
Accuracy and Precision, huh?
I use my Winnie Model 70 .260 Rem with a Benchmark 6.5mm, 8" twist, Remmy Varmint profile, with VAIS Brake to shoot into 3/4" with boring regularity. That rig is bedded into a McMillan HTG with sniper fill stock in GAP Camo. Good enough for my PR matches!
Seriously now, save your money and buy practice ammo! Hit the gym or trails and work on the real weapon system: YOU! You are a machine!
Enjoy the addiction, my great friends!
Barney