Version control, backup, and separating the wheat from the chaff

Hi,
I am an active developer, but new to UE4. I have questions about the project structure and strategies for backup and version control. I have searched the forums and youtube but have yet to find a proper guide on the topic. I am currently working with blueprints so I don’t have any actual code. I plan to transition to C++ in the near future. My question is this:

What is the absolute minimum files I need to rebuild a UE4 project?

Here is what I think I know, but please correct me if I am wrong:
-Everything in the “Intermediate” folder can be rebuilt so is not needed.
-Everything in the “Staged Builds” folder can be rebuilt so it is not needed.
-Everything in the “Editor Cooked” folder can be rebuilt so is not needed.

All “.uasset” files are derived from an original mesh, texture, animation sequence…etc. Provided I have the original file it could be rebuilt as a “.uasset”, but is there other essential information written into the “.uasset”? Is there information about the collision box, materials, or physics baked into the “.uasset” that would be lost if I did not back them up. Also there seems to be multiple copies made of some ".uasset"s, which one is the most important?

Bonus Question:
I would be thrilled if anyone is willing to share with me their folder structure organization. Do you break it down by asset type? Does each object get it’s own folder? Does each level have it’s own folder?

Thanks so much
-scott-