[Q]

I made a neutral racial trait. The main points I included are: athmosphere converter and universal colony module to let the neutral empire colonize all planets in their system as early as possible and use them as efficiently as possible. Then facilities that improve happiness and combat success. The research and construction file go early for mines and satellites.

Just to give you an example:
Name := System Defense Complex
Description := Large comples that improves the defense of the entire system.
Facility Group := Ship Support
Facility Family := 96
Roman Numeral := 0
Restrictions := None
Pic Num := 50
Cost Minerals := 10000
Cost Organics := 10000
Cost Radioactives := 10000
Number of Tech Req := 1
Tech Area Req 1 := Neutral
Tech Level Req 1 := 1
Number of Abilities := 7
Ability 1 Type := Fleet Training - System
Ability 1 Descr := Fleets in this system will improve by 3% each turn up to 30% (only 1 facility per system effective).
Ability 1 Val 1 := 3
Ability 1 Val 2 := 30
Ability 2 Type := Ship Training - System
Ability 2 Descr := Ships in this system will improve by 3% each turn up to 30% (only 1 facility per system effective).
Ability 2 Val 1 := 3
Ability 2 Val 2 := 30
Ability 3 Type := Combat Modifier - System
Ability 3 Descr := Gives a 30% combat bonus to all ships and units in this system (only 1 facility per system effective).
Ability 3 Val 1 := 30
Ability 3 Val 2 := 0
Ability 4 Type := Damage Modifier - System
Ability 4 Descr := Gives a 15% damage bonus to all of our weapons used in this system (only 1 facility per system effective).
Ability 4 Val 1 := 15
Ability 4 Val 2 := 0
Ability 5 Type := Stop Nebulae Creator
Ability 5 Descr := Stops all nebulae creating devices within the system.
Ability 5 Val 1 := 0
Ability 5 Val 2 := 0
Ability 6 Type := Stop Black Hole Creator
Ability 6 Descr := Stops all black hole generating devices within the system.
Ability 6 Val 1 := 0
Ability 6 Val 2 := 0
Ability 7 Type := Stop Star Destroyer
Ability 7 Descr := Stops all star destroying devices within the system.
Ability 7 Val 1 := 0
Ability 7 Val 2 := 0

The nice thing about giving the neutral empires special racial technology is that you can't steal it from them, even if you eventually conquer them.