For those keeping score, here's what I'm changing:

"going to" -> "gonna"

"It's your father's lightsaber" -> "Your father's lightsaber"

"Seventeen?" -> "Seventeen, huh?"

As for the other things, it's often a judgement call and following the principle of "when in doubt, don't", I didn't. For example, Luke definitely does make a sound before "Just Luke", but it could be "It's just Luke" or "No, just Luke", or "Heh, just Luke" (a continuation of the laugh). Not knowing if the sound was even a word or not, I didn't subtitle it.

Oh, yeah, and more on "importances". The script reads "A person of some importance, sir -- I believe", and the only certain thing about this is that's definitely not what's actually said. So it's a choice between two awkward sentences that reflect the flub, or just leaving out the "s/as" to make it less awkward, which is what most subtitles do. I opted for my favorite way to turn the flub into words, but really "as" is just as good.

Thanks for all of the suggestions so far.