1. A 'barrel roll' is a roll where (if done properly) you as a
passenger, with your eyes closed, can not tell you did a roll. The
ball stays centered and if one 'G' is maintained,

I suspect there is more than one definition of a "barrel roll."

The ex-Air Force P-47 pilot I've flown with does a peculiar corkscrew
barrel roll that bears virtually no resemblance to the one I was
taught at Pensacola.

The barrel roll I was taught, and like to do, cannot be done at a
constant 1 G.

There is positive acceleration all the way around (see my post just
above), that is, the stick is back, and the nose keeps coming "up,"
all the way around.

(The ball is in the center all the way around, too, and a glass of
water will not spill.)

That positive acceleration means that more than 1 G is experienced
during those parts of the roll in which the airplane is essentially
upright.

vince norris