@Harmless - Hello, I'm the admin of this site. I am working on functionality right now for a poster image var so that all you would need to do is give the path to your image in the code gen. That may be released today or next week.
All you need to do to put the poster image behind the big play is open the fla file, double click the big_play_button movie clip, then there should be a layer below PlayBTN titled Post Image. You would want to put your image on that layer and align it center. Using this method, you would have to make sure your post image is sized perfectly to your video.
Watch for a new release that has this as a variable. It should be out very soon.
Hope that helps, let me know if you have any more questions.
