I have also wondered about similar questions.

One is that Hubble's mirror is not expected to burn up on re-entry and may therefore hit the ground.

How is this managed with similar spy satellites? Presumably the problem is more acute, because not only do you need to avoid killing someone, but you also want to avoid any chance of falling on hostile territory. Are they actively steered into known parts of the ocean? Or does something else happen (one suggestion with Hubble was actually to fire a missile at it just before entry in order to break the mirror in space).