Wonderful macro!! Yeah, you could crop in more on the flowers but having said that... it really doesn't matter about the bit of leaves missing; actually adds to the macro. ;-)
I'm also sad the top is chopped off since you had more real estate on the bottom. I think you got it right with the distance though, cropped in any further and you would have lost quite a bit of DOF and lost the spatial relationship that makes this a good macro. I might even have stopped down even more on this one. f8 would have been perfect.