Hi Matt
I have the same problem, I need to shoot a scene in a movie theater, in super8 (Kodak Tri-X 7278, B&W 160ISO) and video miniDV.
I found out that with the 35mm projector there wasn't enought light to expose film, and the image on miniDv at maximum aperture with 1/50'' was too dark.
So I think I'm going to lit characters with tungsten lamps (key ligth, fill light, back ligth and just some effect light) and use hands or whatelse for the flickering purpose.
I'm new in cinematography, so this is all I can say about your problem.
I hope this can help you, if you solved your problem, let me know, I'm shooting the next month, so any suggestion is wellcome
Thomas