This took a long time to edit?
It seems to me as if you just don't have the tools to do it.
First off... The only parts of the flash that you should have done in flash was the graphics that couldn't be done without frame by frame in any other editor. (which I hope you did.)
Second... The only thing you did with this film is cut from shot to shot. There was NO audio to align, You didn't do much of a color correction, and considering you used the video in flash..... there was no real need for compression (which can lead to Audio problems and sometimes skipping video frames due to droped images.)
Mind you, the burning of the box was roughly as long as your fight scene (which is too long to be on something boring. Even editing that in WMM would have given you the option of doubling the speed of the burn, and not leaving your audience thinking "is this all that happens?"
So For Future reference:
Get yourself a good Video editing program and do it all in AVI format (or MOV format if you're using Mac) If you're using the better editors they have Keying effects (Green Screen) Just do all your animations and parts you don't have a video for in Flash, and export it to a higher quality AVI, then add it into your movie using the Key or Matte Effects. And stay away from using SWF for video. I have a video series online (which I'm currently in the process of re-mastering and editing) and these tips (which I'm going to be using for a movie very soon) will likely improve the quality of your work ten fold.
Good luck.