There are many possible opportunities to gain ideology
for example: Invasions
Information warfare: benevolent- As few casualties as possible, lives are precious
Biological warfare: pragmatic- War is hell, those people are at the wrong place at the wrong time, the lives of our soldiers are more valuable
Mass drivers: malevolent- ALL YOUR WORLDS SHALL BURN!!!
Next;
Slavery- a very big plot point of galciv is slavery, so slaves on invasions anyone ?
You kill the soldiers, enslave others
Benevolent: Free them, let them join us if they want : gives a portion of the conquered pop based on global approval of the invader and cultural influence, the rest is 'banished'(removed, but in the lore not killed)
Pragmatic: Loot them, ransom the prisoners: Big cash boost
Malevolent: SLAVES!!- Cash boost, decaying production bonus
This is implemented in pretty much any other empire building game, it is a shame its missing from galciv 
Benevolent can get points for high approval, Pragmatic for high wealth/pop(all pragmatic races want wealth), and malevolent from building slave buildings instead of factories...
In GC 2 we had the option to choose how the worlds are governed(democracy, federation, empire)... Should having certain government policies also give ideology ?
Empire- Evil, but morale means less(if you have 0 approval it does not make a significant impact)
Democracy- Pragmatic, more production but production wheel only goes 20 points from the center (you cant tell us what to do!!)
Federation- Good, but morale is super important