You need to work on your debris chunks though; at the moment they look like shards of ceramic or rock. Take a look at how metal bends and tears under high speed, maybe do some soft body/cloth simulation to create an interesting look. Remember that most of the modules on the station are hollow, so you won’t be getting those big chunks but more piece of hull which have been ripped out of shape by the force of the impact and escaping air.
The thing is that debris is pre baked on keyframes. Do you have any idea on how to make it more interesting without going through all the physics again? If there is none, I will do all the physics simulation from scratch. No problem with that. But just in case if you know a way that might help me not redo all that just to save time, please let me know!
I didn’t read the entire thread, but your last image is my favorite. The only thing is when you walk behind a big production like Gravity, we see more easily the lack of realism and details, apart from the fact that it makes the image less original.
If you want to finish this in not too long, I’d recommend to add some motion blur on some objects, level the black to be real black, maybe add a subtle lens effect, and make the atmospheric glow darker and more blue (Look at Gravity’s first shot)