Well there already is alot of posts around, so jere are my thoughts:
Economy: As soon as you're accustomed to it, it works. Good. In the beginnen - like the first three planets - there is not much specialization possible. You need to balance resources to be able to expand further so you need a surplus to all.
Expansion: For meaningful play, you just cannot colonize and build mindlessly everywhere. Having three planets and colonizing two puts a strain on the economy, depending on the traits you picked. Same goes for war. Conquering five worlds when you have four or five yourself? Good luck early on...
Resources: As soon as you get the tech, rare resources aren't rare anymore, but sparse. Yet again, before building check your needs, plan anhead what you are going to need, build, wait for pops.
Fleet: You cannot just dish out ships. They are a meaningful investment now. Losing anything besides corvettes and destroyers might hurt. And using those makes WE go up. Balanced imho.
Starbases: It's possible to get a 20k+ Bastion without Platforms in 2300. With Platforms, dedicated citadels hit the 30k or 40k mark without dedicated ascension perks. This is sufficient for anything midgame can throw at you. In 2325 or whatever my fleets get around 40k or 50k and Bastions without Platforms are at 20k. While you will not beat a fleet twice the size, you WILL kill stuff which translates to enemy WE. While you get none in losing a station. Now back that station up with a half decent fleet...
Space resources: I think they are fine. They keep you going in the early game until you get the tech and pops to make your planets awesome. Space resources are just the icing on the cake later on. The ONLY thing they just finally should get rid of are those godforsaken systems with a total of two or three resources in it.
Don't get me wrong, 2.2 was quite a change and it took me about ten games with a total noob-proof race to get things going. Now I know what I gotta do and while being to lazy to do the maths in detail, get a feeling of what's worth and what I need.