In a way I have found that science fiction was a lot more fun 50 years ago when the cosm was still a big unknown. You know, back when we could still dream about FTL and exotic aliens two worlds over.

At least some uncertainties remain, and it's not only brown dwarfs. I know that we're getting pretty good about pinpointing stars but there's still a lot of error margin in those positions.

Now, as for jump routes: I haven't really decided on my FTL mechanics yet. I definitely will go with a Hyperspace of sorts, and obviously non-free movement. FTL drives can also be used for intra-system "microjumps", and a tentative speed would be 0.5 - 1.5 ly/day. The later depends a LOT on how windy the routes will end up, of course.