So about habitats: Spend 5 years, 5k minerals, 100 influence, and extra food to receive SEVERE penalty to research and unity, brilliant idea!
The penalty you get for extra planets for research unity is overwhelming (10%)! That's the bonus you get for rare and expensive tech or from your precious ethos/trait. Hence, the above is a gamebreaking bug - I've been running on 0 food ever since I spotted this in my hive-mind campaign and my species are doing awesome!
Minerals + Energy still beat (almost) everything.
Oh one of your ships can beats three of mine?
How cute let's see you win with 6 to 1 odds.
Oh you beat my fleet? I have a new one before you even replenish half of your losses?.
In my current Pacifist hivemind (role-play as an extreme isolationist) game I had some really unlucky tech choices.
I've got just Lvl 2 Projectiles, lvl 2 armor and lvl 3 shield, Warp 2, Engine 2 and Computers 2 and jus Cruser Tech.
And got attacked by Evil Purifying Birds.
They had freaking Lvl 5 Projectile, Lvl 4 Armor, Lvl 5 Shield, Wormhole, Lvl 3 Engine Lvl 3 Computers with Battleships.
Just Zerged those ugly Birds. Yeah I lost way more ships than they fielded. But my superior mineral production allowed me to never stop building ships and my energy allowed me to go to about 240% fleet cap before the war ended (also got enough wreckage that many of those techs where free or at least almost free for me).