So in regards to the Vulkar Base thing, two main thoughts on that
First is that I really like the idea you have! Kotor already has plenty of dungeon design where you can explore and use cunning to figure out how to progress, or just brute force your way through, so I think a choice between "find the Vulkar coward in the sublevel to get the card" or "take out a room of like ten enemies to get the card" would fit pretty seamlessly in the game design. I'm all for this idea. Just might require a tiny bit of custom content to make the puzzle about the blaster turrets guarding the garage clearer to the player that some kind of pass is needed
Second thought is about the Twi'lek Vulkar coward in the vanilla game. Honestly, I really like that character. Gameplay-wise, it's just a basic light/dark alignment choice, but I think it adds a nice bit of flavour to the setting and Brejik as a character. A few characters go on about how Brejik's new leadership of the Vulkars has fundamentally changed them as a swoop gang, and I just think it's really neat to encounter an enemy who goes "You know what, I don't agree with the new ways, and I'm not gonna die for a cause I don't care for." It might feel a bit clunky having two enemies who stop combat and offer a "spare me or kill me" choice, but ideally, I'd love some way to retain the vanilla Twi'lek coward while also restoring the human coward who gives you the garage pass card
(I suppose one possible solution to that could be to place the human coward in a room with some enemies, have him do the cowering/fear animation, and then start his whole speech after combat ends so it isn't the exact same situation as the other one? But that's just one idea, if you even would want to use both characters. Up to you, obviously!)