Exporting Selected Drawings

I’d like to export selected drawings as an image sequence. I need drawings 10-18 (the main moving object) without the background as I am now ready to composite the animation using a video editor. I want to control the velocity of the moving object perhaps using behaviors in the Motion software. I need to isolate the specific drawings from the background.

I have exported the movie as an image sequence and it’s almost what I like except that the velocity is too undifferentiated.