I've always looked at Luke as wanting to do the right thing...
He choked the guards, but used the move passively compared to choking someone for burning your toast like Vader would do, and breaking their neck. Hell, he killed people under interrogation... Not the best guy you want handling your intelligence gathering sessions.
Let's make the blind guy a bomb-disposal engineer while we're at it.
The thing with Luke is he's trying, and trying to be good... Lucas has said the character matured, the dark outfit in Jedi showed maturity but he still flirted to the darkside in his duel with Vader (but only upon extreme provocation... And over "attachment", which has become such an immensely HUGE part of the saga as a whole)... But in the end he still comes back...
Hell, he even gave Jabba plenty of time to just let the situation die and give him Solo... I'm still at a loss as to what the plan was if Jabba would've accepted the droids, haha.
His outfits are so different... I don't look at them really representing his growth much, save for the black one. His duds in ESB are ALliance standard uniforms... His outfit on Tatooine's just regular farmboy garb... His Jedi outfit in ROTJ though just seems like his take on a Jedi's "plain clothes". Ultimately he's not well versed in Jedi outfits and Obi-Wan didn't look terribly different from a lotta guys roaming Tatooine (and likely other planets).
I always thought it sorta bit that EU didn't take the black ROTJ outfit further, and when Luke starts the NJO that they don't wear similar Jedi duds to Luke's in ROTJ. Like all of a sudden they all wanted to emulate Obi-Wan unless they were flying.