It should be "how lengths are determined in spacetime" which I assume is just a mundane english second language issue. In the view of GR, all objects follow st

It should be "how lengths are determined in spacetime" which I assume is just a mundane english second language issue. In the view of GR, all objects follow straight lines absent acceleration, and the force of gravity is actually a result of curvature of spacetime. That and the rest of your points that follow are more an issue of not being familiar with GR. I agree the article could have done a better job of elaborating these to a wider audience, but if you've read about GR a bit these concepts will be quite familiar.