Former pro photographer, independent filmmaker.
We love our new toys and want to get them as soon as possible. Problem is camera is not "camera" anymore. It's computer with the lens. It's like installing any new software, there are always bugs and companies will call them BETA. With cameras however it's different, first they go on sale and then you keep getting fixes with firmware, but nobody calls them BETA... For $3000 you'd hope for better...
Find a day job where you can earn enough to live and support your projects. Shoot as much as you possibly can by yourself and with others. Try to buy as little equipment as possible. Dollar saved is dollar earned. Better spend money on production. Rent is a better option. Keep things simple. Learn how to use available light.
Hate to say this, but now all content providers are in deep shit and situation is only getting worse. Making career in cinematography is like winning a lottery. Do it for love, then maybe one day miracle will happen.
Apples and oranges.
Story - location/person - sound/cinematography
I don't know how you can do video editing on 13". I think 15" is minimum, 17" is better. You can find a few very capable gaming laptops from Asus and MSI, video cards with 2 - 3GB of video memory and i7 plus 12 - 16GB of RAM for $1000 - $1500. It is heavy machines usually around 6lb. I am talking about Windows, of course.
I work alone. I do interviews for my docs, but not question/answer. I ask directional question and let people talk, looking at me(I put my face as close to the camera as I can) or directly to the camera and little bit around. In some important parts, I will ask them to deliver their message looking directly at the camera, creates strong message and connection to the audience. I usually do interview at the very end of my filming when I know enough about the person to ask questions and we already have established trust. My main idea is to be invisible in my docs, It's about people I shoot, not about me.