Farm and Mineraldistricts in that order (no generatordistricts - they are not worth it). Always Geneclinic, monument and commercial building. I change my trade policy to 0.5 credits and 0.15 unity. Later i go for 0.5 credits and 0.25 consumer goods (After a certain amount of ascencion percs unlocked). I pick labs over alloy foundries. Depends on gamestate.
Starbases always to cover all trade income in an intelligent way. Means 2-3 tradehub only starbases to cover my empire and inbetween naval-starbases to my capital.
I dont see a point in early wars conquering with the current system. +2 admincap on each system is pretty high if you consider just +2 resources in those system. This has to be adjusted before i consider playing wide again.
You've been missing out, if you think early wars is not viable. Its literally the meta. The meta build is:
fan militarist/xenophobe, distinguished admirality, life-seeded.
3 alloys, Supremacy tradition, nihilistic aquisition. Demand tribute on the first weak person you see. If declined, claim capital and go to war for tributization. If accepted, pick on the next weakest one.
Rinse and repeat and snowball until the whole galaxy is conquered and/or tributized.
If they rebel, its great for you, because you get free claims on all their systems, and don't have to waste influence.