Luke being forced to stand by and watch the Rebel fleet getting slaughtered was also calculated to put pressure on him.
I've long wondered if the Ewok battle was toned down in the editing room. There's a shot in the movie where an Ewok is waving an Imperial blaster, but we never see it being used. Plus, there's unused footage from Jedi in the second Ewok tv movie that didn't show up on the Blu Ray.