The Scoundrel. The Rogue. The Thief. If you are going to have a galaxy full of Knights, law-enforcement or otherwise protectors of the public trust and law and order then it behoves someone to give all those people work to do.
It doesn't matter how advanced we get as a society there will always be the fringe element that does not want to play by the rules, either as a lovable, if "scruffy" scoundrel or the actually evil thief.
By chance I picked up a number of print copies of some OSR books. I grabbed hardcovers of White Star from +James Spahn, Between Star & Void by +Matthew Skail and a softcover of the B/X Rogue from +Gavin Norman.
One of the first things I noticed was how well the Star Knights might work as a Green Lantern like police force. And that the galaxy needed more rogues.
Thankfully Gavin Norman's B/X Rogue is so flexible that we can swap out the bits that make it B/X (sorry) and add in the same bits from Swords & Wizardry. In truth it is not even that complicated.
In the B/X Rogue all the "Thief Abilities" have been replaced by "Rogue Talents". You start with 4 and work up to more. Talents have a high margin of success, only failing under rare circumstances. So that makes the Rogue into something more versatile.
Magic Talents are an issue and should be taken out. But I mentioned before that +Richard LeBlanc's Basic Psionics Handbook can be used to add some of wild talents for rogue talents to create a rogue with some power. Maybe they are a failed mystic, Knight or Sister but still have some powers.
I would also assume that anything like pick locks would extend to their futuristic White Star analogues. Same with pick pockets. Instead of actually taking money out of their pocket the rogue has a device that captures transaction codes and allows them to steal credits.
While our model of a classic rogue is often The Grey Mouser, Shadowspawn and even Bilbo our White Star rogue is Han Solo (to a degree), Neo (at the start of the Matrix), mostly James "Slippery Jim" Bolivar DiGriz from "The Stainless Steel Rat" series, Peter "Starlord" Quill (movie version at least), and 90% of the patrons of the Mos Eisley Cantina...I assume.
Now we have a Scoundrel class already which fits some of this thanks to Tenkar. But the rogue is something a little different. This now practically begs someone to build a Bounty Hunter class ala "Cowboy Bebop".
Plays Well With Others
A total cheat on my part here. Both White Star and the B/X Rogue are so flexible that feats of Game Master legerdemain are not needed here.
There are some features of the B/X Rogue though that make it more suited for White Star than saw the thief from S&W. This allows for differences in Starlord and the Stainless Steel Rat.
Actually this gives me an interesting idea, but that is for another post.