I actually had thought that breaking in a regular car would disengage the engine... until I tried it.
Not a good idea. Disengaging the engine means lower control over the car, as the engine in lower gear actually helps you with braking. The injection system cuts the fuel flow, the engine is decompressing warm air, which slows the car down. Very convenient when going downhill. With the engine disengaged, the only thing that's slowing the car down are the brakes. Leaving the gear in saves fuel, brakes and the engine health as well. Additionally, in critical situations you can hit the gas pedal and accelerate immediately.
The use of things like rotating bearings and electric current (for transmission of energy) might enable a self replicating machine to operate much more efficiently than life.
I'm not so sure about this. Bacteria use something like a rotating bearing for anchoring the flagellum to the cell membrane. For some reason, this evolutionary feature is absent from eukaryotic organisms (their flagella are undulating, not rotating structures). Maybe they are not so much more effective.
A monstrous yet immobile creature who lives in an exposed pit in the middle of a lifeless desert, waiting for large animals to apparently feel suicidal and trek out to throw themselves in? Yeah, not so much. Not every Sarlaac can count on an intergalactic mob boss to feed it tidbits.
Has this guy never heard of the Antlion and it's sand-pits? (no, not the hl2 creature)
"For a male and female to live continuously together is... biologically speaking, an extremely unnatural condition." -- Robert Briffault