A shorter radius on the tip puts more english/draw/follow per unit of offset from dead straight onto the center of the cue ball. Which is great if that is what you want, and not so much if you did not want so much.
This difference is negligible. You're grossly exaggerating its importance.
Those with very pure strokes can get away with shorter radii; while we of more average capabilities cannot get away with it often enough.
A dime shape vs. a nickel shape does not make hitting the cue ball accurately or controlling spin appreciably harder for any player.
An absolutely flat tip will not impart draw/follow/english no mater what the offset.
This is untrue. Once the edge of the tip is outside of centerball the tip will spin the cue ball. Hitting on the edge of the tip doesn't automatically mean you'll miscue.
A tip with a very small radius (say 1/2 a dime) will miscue very easily at little offset.
You couldn't put such a small radius on a normal tip. Any normal radius doesn't miscue more easily than any other normal radius.
Generally speaking there's no practical playing difference between a nickel and a dime radius (or even between a quarter and a dime radius) on a normal size tip. All this handwringing is about nothing.
pj
chgo