Modding

Well yes, it would require full access to the source code. Many of the features you listed would require a programmer to do the additions to source code, or bind a tool to make it possible for someone to make some changes, like make it 100 sectors instead of 20 in a map for example.

Binding a tool to do it requires even more work than simply making a change to the source code, since the tool has to make changes to many things. For example, if a modder wants to change a map from 20 to 100 sectors there has to be some reasonable changes to how enemy ships are spread across all those sectors, and how the difficulty ramps up. Otherwise it would be very boring with 1 ship in every sector.

Well now if you take that into account the tool has to make it possible for a modder to change the percentages and the algorithm to spread those enemy ships in a meaningful way. Someone has to write this code, then fix all the bugs that appear when modders start to use it.

This is very time consuming.

So in short: It would require us giving full access to the source code, including our own game engine, which we have built for 5 years now. It's not something we can do.