Learjets, Flight Test, and Hollywood
Some great questions and observations! As a former military test pilot with a type rating in the Lear 20-series, I can offer a couple of thoughts on some of this. For commercial ops, virtually all biz-jets are certified with a two-pilot crew, but the fact is that they can be safely flown by a single pilot with the only added risk being the loss of "meat servo" redundancy. The guy in the other seat on the film may have been another rated pilot, or may have been a flight test engineer or even a maintainer. You'd have to ask the company about its policies on that.
The early Lears had crappy full-stall characteristics, so they had stick shakers/pushers installed to keep you from getting that far, but recoveries involved using coordinated rudder and aileron to get the wings back to level. The pilot's feet were not visible to me as I looked at the video, so there is no way to tell what he was doing, but consider this: at about 36:39 of the clip you see the yoke being worked frantically, but if you look carefully, you will also note that the attitude indicator is frozen solid at a wings-level, nose-high attitude. In Hollywood, sex sells, and so does pucker-factor... real or not. Cut to the simulator? Your guess is as good as mine.