Ditch the shadows you've got... you're overthinking them...
duplicate the keyed subjects
The top layer stays the same...
flip the bottom layer and line up the feet
Skew the perspective of it to match the floor plane.
Turn it pure black, give it a slight blur and lower the opacity.
No need for overlap or trying to emulate shadows on the subjects as they will already have shadows on them from the other actors who were in the same place... just the "contact shadows" on the floor were necessary.
I'm making a 22 minute version of the production for the SyFy Channels's pilot pitch where the film should be between 4 and 22 minutes long. Nearly half the footage was cut in the new version. It's a chance to win $5,000. So, I'm taking a shot at it.
Where are you getting this info on the Syfy pilot pitch? I've done a search on google and the syfy website, but can't find any info.
Also, this is a big improvement to what the footage was months ago. Good to see you're still chipping away with it.
I always think of it as the scene with Peter Pan sews his shadow back to his feet when I'm doing it.
Both of these tutorials ignore the lighting/shadows of the shot they're comping into... and make the shadows a little strong for my taste... but this is the technique I use. Using multiply as a composite mode will help blend the shadow into the background better as well.
This is a photoshop tutorial:
This is for Final Cut X, but shows the meat of the technique starting at about 12:45