Hi Nels.
You seem to have a pretty good handle on the game vs reality thing, so I'll skip this. Here are the choices that I generally make when trying to make a 'realistic' game.
"Space is big. You just won't believe how vastly, hugely, mind-bogglinly big it is." (DA) Start with an immense galaxy. This doesn't even remotely approximate reality, but it is what we have to start with.
There are a lot of stars. We know this. I set stars at 'abundant'.
The aforementioned stars occur in no real pattern. Some are in globuar clusters, others are widely scattered. I usually choose random. Clusters, more often than not, mean early wars, scattered generally gives more time to advance.
We have no idea how many planets there are in our galaxy. We've found over 300, but all of these are gas giants. (Like Jupiter or Saturn). This is a tiny fraction of a percentage compared to the number of stars, but there is a lot of leftover crap in the galaxy, and our own system has a 9:1 ratio, so I usually set planets to 'common'.
Habitable planets are rarer than rare. (If they even exist outside planet Earth)
Asteroids are common. We know of many thousands of them in our own system.
Define 'anomaly', and set the game accordingly.
These are the only settings that have even the most tenuous thread to reality. Set the rest as you see fit; your opinion is as valid as mine.
Above all, remember that this is a game, not a simulation. It is meant to be fun.
Best of luck to you, and if you have any more questions, don't hesitate to ask.
