Jim
Although I can't answer your first question about keeping track of
all the dances, I can say something about what constitutes a new
dance. I remember Ted Sannella saying that a dance is new if it has
50% new or unique choreography. By his definition if 50% or more of
the dance is different than any other dance then it's a new dance.
If a dance has less than 50% it's a variation.
He didn't go into any more specifics and I wasn't wise enough to ask
any questions. But if you look at some of the old dances like
Petronella and Hull's victory, they have identical B parts and unique
A parts. The same applies to Chorus Jig and Rory O' More.
Squares can also follow this 50% rule. For example there are a
number of squares like Queen's Quadrille that have unique A parts
while the B part is circle left half, swing corner, promenade.
T