You might consider dropping Deena Shan for Anakin FS, who gives Renewal to the SS, and also Mettle to nearby force-users (and a mettle-evading SS is so annoying to play against!). Another option is to drop Chewie for Ferus Olin. Ferus has 20 less HP and has melee attack, but he has a whole lot more dmg output, he benefits from Anakin FS (mettle), and he costs 3pts less, which allows you to fit another Mouse Droid into the squad.
There's no question: Luke's SS with a solid bodyguard backing him up is very difficult to take down.