With 43 kcal/100ml you need about 4.6 liters or 5 qts to satisfy your caloric needs (2000kcal/day). If you even out the intake over the whole day, alcohol levels should be low enough to keep you functioning. Beer also contains a bit of protein and low levels of sodium, potassium and magnesium.
Long term, you’ll get scurvy after a few months due to lack of vitamin C and liver cirrhosis from the sustained alcohol use.
IIRC from the “What we left behind” documentary, they were shot on film. They even had a few minutes of HD material scanned from the film reels. It’s the CGI that was baked only into the tape version that makes it so difficult to do a HD remaster. And why they went back to the tapes when producing the DVD release.