C:\Program Files (x86)\Steam\steamapps\common\sins of a solar empire rebellion\
Sins of a Solar Empire Rebellion Dev.exe
Which is the development version of the game with many awesome features.
To access the debug menu press Ctrl+Shift+.
Most of the cheat features are in change galaxy.
Using setup quick play will give you all the neat stuff to yourself and enable some overrides to quick build and such. But the AI also get theses abilities.
Just play around with it, its tons of fun.