Strava auto identifies a segment if it's a "category" climb, by whatever category criteria it uses to identify segments automatically.

Yes.

Its hard to rename them. I haven't figured out how to do it.

Sometimes the times it generates may be inaccurate, or accurate by certain frames of reference, because the effects of gravity and the speed of the satellite causes time dilation.

If the cyclist goes really fast, read: has a really great average moving speed, additional dilatory effects of time will occur.

Its really quite simple.