We all know Kurtz and Lucas clashed in a lot of the story telling points. And once Kurtz was out of the picture for ROTJ, you saw how milder and gentler that movie is compared to the other two.
Nope. It had nothing to do with Kurtz. Otherwise why would Leia shoot those two Stormtroopers at the end of the Endor battle "in cold blood?" They weren't even laughing about the idea of her "dead body," they just asked her and Han to stand up and she blew them away! What a murderer!