IIRC, the Dark Horse comics adaptation didn't tweak things too much. There really isn't anything contradictory except for the first encounter with Vader. Mythology is chock full of siblings who don't know they're related. ;)

If Disney starts looking for story material to adapt, this would be a good place to start. I worry they would make it less dark than the novel though. Vader making bookends out of Captain Grammel was pretty shocking.

I've often thought Frances Sternhagen, who played the doctor in Outland would make a splendid Halla. The Dark Horse version even looks like her.