Rocks are powerful weapons, as long as they’re going fast enough. Just ask the dinosaurs what their opinion is of fast-moving rocks. And they also tend to have useful materials inside that can be used to make other weapons.

Holding himself hostage to escape is not something I would have thought Han would do. Jim’s character definitely, as long as there didn’t seem to be any reason to simply not shoot him anyway. Exhibit A for that instance? Right here. It’s round enough to potentially be a thermal detonator, but with Proxima’s bad lighting, I can’t tell for sure.