1. If you're playing with the Distant Stars Mod, head into the mod's folder and open the GameInfo folder and find the gameplay.constants file.
If not, head to the install location of the game. (In Impulse, right click on any of the SSE icons and select 'Open application folder'.) If you plan on only playing with both expansions, go into the Diplomacy, then GameInfo folders, and then find and open the gameplay.constants file.
In the file, find these lines: (They're about 3/4s of the way down, lines 445 to 514)
buildSpeedData
cultureSpeedData
researchSpeedData
incomeSpeedData
shipPhysicsSpeedData
diplomaticPointsSpeedData
Lower the numbers on the Slow Scalars. Save (To a mod if you're editing the non-mod install file), and done. If Distant Stars or the game updates, you may have to do it again.
2. Diplomacy. SSE launches without either expansion, Entrenchment launches with only that one, Diplomacy launches with both.
3. Latest version should say which it is compatible for. If you get Diplomacy version (If that version is out yet) then you don't need the other versions unless you plan on playing without the Diplomacy expansion enabled.
