2. Luke has had a year or so to come to terms with Vader being his father, to have the yearning to know his long-lost father that we see all the way back in the first film be realized in the unswerving love that brings Anakin back. Leia's had a few hours to try to process that the scary dude she'd known and avoided as a senator, who tortured her for information about the Rebels, who helped destroy her entire damn planet, who froze her boyfriend... is her biological dad, even though he assisted in the cold murder of the man who raised her. I don't think "respects" are high on her list of feelings for the man.
3. Well, the saber Luke lost on Cloud City ended up in a waste-collection station somewhere. The one Vader lost on the Death Star II was nuked a few minutes later. *shrug*
--Jonah