[Q]

If you like neutral empires as I do (I might have a sympathy bias!) you may try the AI modification I posted in the Mod section.
It's not a big deal but it should make a better defense by using more units and not reseaching items that are less useful for neutral.
However if you want a really tough neutral empire I recommend that you use the map editor and create a system with sphere/ringworlds for them as home system!
Any feedback is welcome.