I will not comment on (1) and (2) but (3) is wrong. I don't think that's even a 737 MAX on the picture. 737 was originally designed to be low to the ground to

I will not comment on (1) and (2) but (3) is wrong. I don't think that's even a 737 MAX on the picture. 737 was originally designed to be low to the ground to make it easier for ground crew to "bulk" load i.e. just throw stuff into the cargo area. The reason why 737 could be so low to the ground was that they were using turbojet[1] engines. Turbojet engines are very slim compared to new turbofan engines used on later 737 generations. When they moved to turbofan engines which have bigger diameter they needed to move them higher up from the ground. So they moved the engines in front of the wings. To gain even more ground clearance they moved accessory gearbox and fuel pump from underneath the engine to the side. That's why engine appears flat on the bottom. Obviously the engine is still round because the fan is round but the lip is flattened. All this allowed Boing to fit more efficient and quieter engines to 737 without extending landing gear. The shape itself does not generate much aerodynamical lift if any. On the 737 MAX they actually extended the landing gear and it does not feature "flattened" engine shape any more. [1] https://en.wikipedia.org/wiki/Pratt_%26_Whitney_JT8D https://en.wikipedia.org/wiki/Pratt_%26_Whitney_JT8D