I also think I saw the missed grappling hook... but I have always been willing to accept that I am mistaken about that one. My justification there, is that in every other movie where someone attempts to lasso something, they miss the first time. So it makes sense that our minds could fill it in, and then remember it that way.

The brief shot of Vader's ship spinning and then flying away made me go "whoa" when I first saw it on the VHS. Even after seeing SW three times in Utah, I assumed he had been killed. It shocked me to later see him clearly survive.

Between Biggs, hook, and Vader, I believe if one of those three scenes is ever shown to have made it into a theater in 1977, to me it would be strong evidence of all three. Until then, I have to agree that it is pretty hard to accept with nothing having materialized in all these years.