Galaxy Map setup, how to find the right one?
 

Usually I "copy" the quadrant/system txt files from AIC into other mods to increase variety. Most of the maps are from Fyron's quadrant mod. Now, what I am searching for is about this:
Balanced large ideal Quadrant (nearly), but I would like to see some asteroid belts and/or more asteroids at all. Possible? If so, what do I modify to accomplish this?

Bonus question: I tried the same with Masters Mod, but the maps are invisible (pitched black), I do not see the planets in the system screen and the lower right screen (system overview) is empty also. What happened here?

Re: Galaxy Map setup, how to find the right one?
 

Just quit and start a new game.

That black-screen thing sometimes happens the very first time you run a new mod. No idea why, but it only happens once.

Re: Galaxy Map setup, how to find the right one?
 

You need to find the quadrant entry in QuadrantTypes.txt to see what system types are used. Then, find those systems in SystemTypest.txt and add some asteroid entries to them. Copy them from a system with asteroids and renumber them appropriately.

For more information, see SE4 Modding 101.