Huh, reading this thread I've had a far different experience than everyone else here, and that's why I'm starting to love this game, it's just so diverse it seems in what can happen and what a playthrough is like.
Slow and steady expansion from a huge lake on a water-restricted world, so I made hella cash just selling water to traders. The units, organizations, and logistics are really immersive, and all the little feats too you can add to the units adds character and flavor to them that I start to remember them by.
PP was very abundant early on but once I started needing more leaders for expansion (governors) and generals and diplomacy strategems for convincing the majors not to gank me, it started draining really fast.
Like that you can make bad things purposely happen to your empire for fate points. Kinda sad to hear that the more advanced archive strategms are being removed. Right now I'm sitting on a mobile chemical launcher unit that I really want to buy, and don't think I would have gotten it in the newer versions.
And raiders are indeed pretty chill. I've had more trouble with nomads actually who seem to be everywhere that has good resources. Nothing my motorized and mechanized rifle brigades can't handle
I actually befriended a raider early on without realizing it, and balanced the sovreignty of my country with keeping good relations of them, and I actually really like the diplomatic game in SE. Got a client state eventually out of that raider minor. Have two majors on my border now, one is apparently theological dudes who I can't convince to not be hostile to me no matter how much relation I give them, which I assume only delays their attack, and someone to my north with the BLACKMAIL mood who tried to blackmail me and failed... and those two are at war with each other so right now I'm just stockpiling and getting armies built on both borders so that I can swoop in once they're both exhausted from their war and run down their forces...
As for minors, they seem pretty weak once you get past initial early game, as long as you avoid the AI sentinel ones. Generally I would avoid invading nomads though unless they have good resources in their lands, since they don't seem to have large cities, or any cities at all really. I had a protracted war with a nomad faction early on that didn't get me much other than a vast expanse of land and a new border with a major, and my second war with a farming minor ended almost instantly once I capped their capital in the first turn because it was the first part of their nation I explored, and got a whole city that was almost the size of my capital.
I do like the way fog of war works, in that you can't really see the definite borders of nations you encounter, since the game just assumes they extend out infinitely from you until you explore them. Placing spies in nations you fight really helps clear up their fog of war and find their cities.