Setting aside the ideas for the plot, could games like Eve, No Man's Sky, or Elite: Dangerous accomplish the same thing if they used actual astronomical data?
They can't. In order: Eve is a murder/capitalism simulator and has almost no physics in the first place. (There's 3-dimensional positioning, but you can fly through planets and shoot through other ships as much as you like; also the entire world is static.) No Man's Sky is 90% an art piece with some added murder simulation. Elite: Dangerous, also a murder/capitalism simulator, only unlike Eve it's more about the imme…
KSP "only" has a sphere of influence model. That's why there aren't any Lagrange points anywhere in the solar system.