If you find yourself somewhere where you can't gaffer down your pedals, that rubberized non-slip matting they make for kitchen shelves:
works very well to stop pedal 'creep'! Just cut to the appropriate size...

Donny, are you wedded to having the volume pedal at your left foot? If you can get away with it on the right (generally, if I'm doing organ, I'm not using the sustain pedal at the same time) then bring the EC-5 further to the left and bring the expression pedal over to next to the sustain (maybe on the outside). That's how I set mine up.

Admittedly, the stand isn't helping. Maybe a move to an X-stand will give you room to get them further apart?