I'd throw it in the freezer for rendering and still have a fire extinguisher standing by. My MacBook Pro is no wimp and I always fear it's going to burst into flames on big renders.
GH3's and 4's are absolute crap in low light. Fine in daylight or indoor with a good fill and a flat profile, but I hate them in low light. Not sure why anyone would want this, or the low end Black Magic, as they're both producing FPN from hell in low light. I'd stick with a 5D or a 7D.
As a producer evaluating reels to see if I want to hire a shooter, I want to see different kinds of shots in various lighting conditions. I want to see a resume that shows you have experience. At that point, I care nothing about your personality. That will come across if I call you in for an interview, and if you have a great reel, and appear to be someone who'll take direction and be easy to work with, then I'll give you the work.
This seems more like a video cover letter, which is a clever idea, and you do want to let your prospective employer know you understand their business and have a passion you can bring to the position. There's just not enough there (in terms of sustained shots that aren't in a traveling vignette) for me to evaluate if you're a good shooter.