I think your problem is that it’s just a hideously over-nested-comp project. There are comps in comps in comps – a ridiculously huge amount of layers to achieve something that just doesn’t warrant it.
Without remaking the project from scratch, I think you’re just going to have to put up with long render times. It would probably take longer to remake it than to wait for the render. Make sure you do a super-low res. render to check everything works before setting off your big render.
– Paul