Thanks for the comments! I think you're right on all counts.
Ideally I suppose there should be a companion document with some samples of play. This could demonstrate how the map is filled out, and how the stat-blocks interact with it. I tried to use the stat block icons in line with the text to provide some breadcrumbs, but actual examples are probably necessary.
You are correct that there are no explicit instructions for using the game with multiple players. Some thoughts I had involve either playing collaboratively and coming to group decisions for all tasks, or dividing up responsibilities such that perhaps one player sets the course and another chooses how to spend artifacts.
The intention behind the light-lag is that you never know exactly what the conditions are on any world, until you get there. The further away it is, the greater the change might be when you arrive. I'm not sure it bears tracking as I instructed to do, though. All you really need to do is count the distance from your ship and it is self evident.