While I wholly agree with your the rest of your post, I have to take issue here. The Orbiter API is so flexible (and bless it that it is so) that you can make it behave almost any way you wish. There are any number of addons that violate known physics in outrageous ways (Star Wars physics, jump/warp/FTL drives) so saying "its in Orbiter, therefore it abides by real physics" just doesn't wash.As for the Delta Glider, aside from its magic engines, it still abides by real physics during flight, since it exists in the Orbiter sim. You could not use Orbiter to simulate, for instance, the fake gravity on the Russian station in the film, the docking sequence where the vehicle docks upward with its main engines burning, or the 10G turn around the Moon as depicted in the film.
And, for what its worth, I think the current API could be made to simulate the gravity inside the Russian station by the use of the GetMass function, the AddForce function, a vector field of some sort describing the way gravity varies inside the station (it could even be a random vector field to really get the effect shown in the movie ) and some matrices to transform that vector field from the station's reference frame to the reference frame of the UMMU (or whatever) that is inside the station. I can't imagine that it would be worth the trouble though...
FWIW, I tend to use the more "realistic" of the Orbiter addons since the above mentioned addons are generally more fantasy than my role playing is prepared to tolerate.