A prominent corporate filmmaker from Mumbai with over 27 years of experience and strong advertising background and is technically robust with over 3000 productions accomplished for top international brands and diverse industries. I am all self-taught.
Canon colors are vivid and accurate. Sony colors are fake but stylized. Despite this, I dropped my Canon 5D and went for Sony A7. The notion is that my audience likes novelty and not anything that's conventional. Canon pictures look similar to your mobile phone pictures. They are not different.
You are wrong!
Whether you play at half or a quarter resolution, your PC performance for a heavy 4k file will remain the same. Because your PC has to anyway deal with the same file, read the entire information from that fat file and transcode it in realtime to show something on the screen at a quarter resolution. You may save some number crunching during displaying details, but file operation remains the same.
On the contrary, proxies save on the file size too. Additionally, if you choose a lighter codec then it become easy on the CPU too. Therefore a proxy is a judicious balance between CPU and i/o jobs for the PC.
Dialogues or No dialogues? It cannot be black or white. My philosophy is less is more.
I have been making documentaries for 30 years. The most important part about making a documentary is bringing novelty every time you make one. No one will watch your doco, if it looks similar to the last one.