Just thinking out loud here... Like in my oldschool BC n00b days (8 years ago)... for the flashes of light, maybe put one of those invisible, non-collidable point ships in the nebula, the ones some of the Machinima makers use.
Make it non-detectable, give it very poor sensors (so it's weapons routinely miss the mark) and arm it with loads of invisible torpedoes that do very low damage.
The torpedo script should set it's colour to white, it's speed fast, and make the light cast by it as bright as possible (I'm rusty on the parameters of torpedo scripting). The sound should be a crackle (or a few torpedoes with a selection of crackles) sampled from the nebula thunder in the film.
The Point-ship's AI should make it attack people randomly from time to time.
Net effect: Every so often, a crackle goes off, and the hull is lit up white, like in the film (pity we can't get the nebula clouds to flare up too!).
As I say, just thinking out loud. Use it if you like
