(3) players hit (3) different sets on flop (10 handed)

[BBD]

As to your question about 2 players flopping a flush. I think the math would look like:

9C3 / 48C3 that is 9 of you and your opponent's suit remaining in the deck (as you both hold a suited hand) three of which will be on the flop / the total 48 card deck drawn from 3 times
9C3 = (9)(8)(7) / (3)(2) reduces to (3)(4)(7) = 84
48C3 = (48)(47)(46) / (3)(2) reduces to (16)(47)(23) = 17296
84/ 17296 = 0.00485 or 0.485%

thus you and your opponent will both flop a flush 0.48% of the time you both hold a hand of the same suit.

again, you may want to post this in probability to make sure the math is right but it should be something like this.