I do everything in my mod, mapping, making weapons, ship scripting bah bah bah. You should read the forums before asking, if you can't find what your looking for alot of us would be happy to point you in the right way towards your goal.
You are NOT going to learn how to make a very ......."super" map in a day or even a week, the goal is time. It took me at least almost about 2 weeks to learn the basics of map building, very long story becuase I started my modding by hand and then found out I could of done the whole thing within an hour with a program.
I would suggest you use Freelancer Explorer Frist or Freelancer System Editor to learn what the ini. files look like and to get the feel of how it is all writen and be able to read it. Make basic maps and enjoy them. Then work your way to more harder task to make a system feel vast and colorful.
Now your other question about you wanting to help people make the stargate mod.....well you'll have to find the makers and ask them.
But you should find those systems programs and learn the basics.
Good Luck,
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