To Drew Wagar: Wow, thank you for the offer. I may just have to take you up on it: I'll take all the help I can to better understand tie-in fiction, and you'd be a great source of wisdom.
To Shadowdancer: You have fantastic points that are very helpful to the discussion. Keeping things in line with canon is, of course, a major concern pertaining to tie-in fiction. It's a good point that writing tie-in fiction as a first novel may not be ideal if you haven't been practicing world-building, and have a keen understanding of what canon is, its involvement, and its importance. Personally, piecing together a robust reference guide sounds not bothersome to me at all, but exciting. In fact, those steps are some of what makes writing tie-in fiction so alluring. Fortunately you get a good head-start by deep involvement in the game itself, as well the Elite Dangerous Wiki and other fan resource collections. That being said, such resources are far from fool-proof and one would have to step lightly and obey instinct. And by that I mean understanding themselves and their own ignorance. Should a scene drift into areas of the universe, the science, or the politics of Elite that you don't grasp confidently, it may be time to pile on more research (or do an artful dodge of the subject in general). Novels in new systems with entirely original characters would also avoid many potential pitfalls (like your example of getting someone's hair color wrong). But such fresh novels will still require the novelist to be familiar with, say, what a first FSD jump would feel like And details like that would require looking into lore and even the more popular novels to maintain some form of consistency.
Perhaps, us in the creative fiction side of things, could follow in your ideas and create a community-wide "official" reference guide. In fact, I may have seen one around here somewhere. . . If I did, I'd have to give it another look, and perhaps the community could expand upon it. In the industry, such a concept is usually referred to as "the series Bible." Many television shows, such as Battlestar Galactica, had one for their writers and guest writers, which I subsequently modeled my own novel series "bible" after.