Not in anyone's nightmare
You asked three questions, which makes it loaded. The complex answer is that if we all agree that virtually every shot is taken with the cuestick slightly to more than slightly elevated, then by the potential energy formula, a loose stick, cue dropping type of stroke takes less energy and therefore less effort to stroke with a balance point further back. The downside is that it takes more energy to get and hold that stick to the elevated (or slightly elevated) position to begin with. Choose your battle wisely.
What difference does an inch either way make? From a percentage point difference, a really small percentage. But most experienced players can feel the difference of an inch immediately.
Did. Potential Energy = mgh. But, it doesn't matter from a study of balance alone. Let's not make a false conclusion.
The concern is simply from a feel standpoint. Your question is the same as why a baseball batter swings a bat with a thin vs. thick handle or bat head. They're going with feel during the swing. All of the bats in baseball can get hits over the fence. But, how a particular individual is able to swing a particular bat is part of the equation of their particular optimization.
Even a small percentage, a human can discern a difference. Whether that difference is detrimental is a completely different question and answer for each individual. For me, once the balance point gets too far away from comfort zone, I cannot hold the cue for much longer than a few strokes.
Same as any sport. Same as pool. Throughout our experience, we as individuals will be able to tell what type of parameters feel best to them.
Fred
I agree with Fred.
I am not gonna put science up as my backer, just my personal experiences.
How much difference is there between 12.5 mm shaft and 12.6? I can tell the difference. I don't know how, I just can.
I was recently in Pete Petree's shop and he took the buttcap off of a cue he made and it was only barely one ounce. I took the cue in my hands and stroked it and it felt like a completely different cue. It basically felt like an incomplete cue with something missing from the back.
I personally love to play with full spliced cues and think that putting those points in makes the wood more stable which is why they were done in the first place. The large area of glue surface made it an ideal way to join two pieces of wood together without screws or adding any other type of joinery. Half spliced cues are simply an abbreviated version of doing full spliced cues and therefore get only half the result. Feel and all.
During the ICCS, Bill Schick, Jerry McWorter, and others brought up the fact that we are essentially copying those of the past. Why do cue makers today still build cues with points, and would we even be doing it had it never been done before? Why wouldn't we be making waves, or egyptian style mortise & tenons, or japanese joinery? who knows?
The only thing I can think of is that there is a basic fundamental of joining a round wooden dowel to make it first of all, fit together in the best way possible and stand up to the test of time and abuse they way a player would handle his cue.
Basically, with the balance point, I think if a human (experienced player) can detect variances going from 12.5 to 12.6 mm, or a difference in the thickness of a tip and even whether or not a joint face is not completely faced off perfectly, is a tribute to human sensitivity and all boils down to personal preference and what one likes over another.
Why does a person like chocolate and another like strawberry? I like pistachio almond ice cream and all I can tell you is that I like the flavor. I don't necessarily know why I like a full spliced cue over any of my 3 piece cues. All I can say is that there is more of a resonating tone that vibrates with a ton of feedback into my hand and up into my body. That type of feedback is something that an experienced player needs. That as well as the use of deflection and touch is where I get a huge part of my enjoyment.
sorry if I rambled on, but I was just trying to speak from the heart.