Ooooh, that's new to me. Makes the GH4 seem even more tempting.
Read more! Talk to people! From there you will find whatever you need, and maybe more. Good luck with your project!
Yeah, I agree with Guy. The audience doesn't care if it was shot on 35mm or on a BMPCC. One of the many definitions for the word "film" in dictionaries is also "movie".
I'm not even sure where to begin because comparing manufacturers is a very broad stroke. There's just so much to consider even before you get into the technical specifications of each of the cameras available from these brands.
I'm pretty sure that was achieved in two different shots by masking in AE.
It's just higher bit footage. The GH4 doesn't do RAW... for now at least.