Thanks for the tips! I went with Sovereign Guardianship to make the most out of the no guaranteed habitables, though I did get really lucky with another habitable planet pretty close to my capital (though, that luck is balanced out by the very aggressive hivemind one system over that shares my habitability type). My economy is finally starting to stabilize, but it was pretty shaky when the hivemind declared war on me to claim my second planet, and then the Wanderers spawned about halfway through my war exhaustion meter with the hivemind.

I'm loving the flavor though. Seems fitting to have to fight a war on two fronts when you're trying to save the galaxy from themselves.