UBH was right for #1, that's what Lucas originally said. Yet after fan outcries and talk of alien descrimination Carrie Fisher presented Chewie with a medal on MTV, that was in 1997 as part of the Special Edition hype. For #2 it was explained in Shadows that despite Vader desperately wanted Luke to join him on the Dark Side he needed to first test his strength in the force before making such a proposal. If Luke could be easily killed there would be no point in converting him.