They can sting, but they (anecdotally) sting less readily than some other species of wasps. I’ve been around them all my life and never have been stung. But, I’ve never intentionally messed with them. On the other hand, I’ve been stung by a couple other species that were far less patient with my presence in their general area.

If I am understanding the chart here correctly, bees are not a type of wasp. Bees, wasps, ants, and sawflies are all Hymenopterans, but distinct from each other.

No, they let them fall to their doom.

How is parasitism any worse than straight up eating something else? Also, house cats kill for fun. Should they go extinct?