But that presumably doesn't handle the relative motion of the stars, which makes the problem even trickier, since the distances will change as you travel, no? Or is my astronomy off base here?
I think your astronomy skills are correct, but if we have to worry about actual travel then you would also have to consider things like fuel capacity, refuel opportunities, the fact that you probably don't want to actually fly through a star but around it, etc.
I think it's still valid to have a distinction between travel logistics and having a route that's at least theoretically possible. I suppose what they've calculated would work with a star gate like system, but then I'm not sure what the point of having minimal distance would be.
Isn't the flying around problem just "e" since it is so many orders of magnitude less than the distance between stars that for this calculation it is irrelevant anyway?
That's not true. The tour is 16.2 billion light years long, so even at the speed of light, it would take more than the current age of the universe to travel. Stars will move a lot over that period of time.
That doesn't make sense to me. If you're assuming instant travel, then of course you don't need to account for stellar drift. Your response talking about stars "moving on roughly the same trajectory" doesn't make sense in that context. And anyway the GP was obviously not talking about instantaneous travel.