RE Bespin escape

http://www.youtube.com/watch?v=61vjrvcTCRU

at 0.52 you have added a spark type thing to the storm trooper that gets hit and in the original no effects were inserted at all so your obviously aware of the neglect in the original.

I found some footage of pyrotechnics you could perhaps use that does seem roughly equivqlent to what was used probably on set when filming or alternativley you could hire a pyrotechnic detonator and buy the actual pyrotechnics for not that much money and green screen the actual pyrotechnic detonating. Find a stage Lighting Hire company for this.

anyway the clip that might work 720p white air bursts

http://www.youtube.com/watch?v=_rP56CIsBTA

I like the 3rd one personally, but this is the sort of effect needed at 0.52 in your clip I think to keep it the same as the other storm troopers getting hit by lasers. Hope this helps....