So what to dance to Rumba music you should decide following these two rules:

1) Man dances what he learned from his actual (or if he hasn't one at the moment - last) teacher.

2) Lady dances what man is leading.

I think there is no other way to decide, since you American guys don't use "International Style" all of the time.

(But I sadly have to admit that even in Germany, where most studios follow International Style, some of them teach a "Slow" on beats 1-2 and not 4-1 for beginners.)

Whether the Rumba is Square or Intern. style-- the musical rules do not change--- The commencing direction, if danced on the first bar, should be backwards on the break.
If square to the side ( on 3 and 4 )

For some unknown reason , when the Bolero was taken as the template for the current style, its direction was changed .( we did the same thing with Cha )

As to what to dance as lady ?-- whatever the man leads ! ( I hope )

It's the same music (except the tempo that may be a little bit faster in American Style) BUT NOT the same timing of the step's rhythm in relation to the music. Int. Style: "Slow" step on beats 4-1, Am. Style: "Slow" step on beats 1-2 or 3-4 depending on the dance studio. I think the only thing all styles have in common is that the rhythm of the steps could be counted as "quick qick slow".

Thats exactly what I just said !!---

by the way-- Bolero can be appreciably slower .

I worked for both chains for over 40yrs ( on and off ).

The individual who determined the musical construction in the dances taught, for Freds, was John Monte-- his brother was the famed composer Hugo Montenegro.

I worked in NYC whilst John was the National DD for the chain ( I was DD for one of the NY schools )