I am with you here, I played every other "Endless" games, apart from Endless Space 2, and I find this one confusing:

- I have no idea why creating an outpost or a quarter will change the yield of the surrounding hex, most often than not, removing the science ones, which is why I put the city/outpost there in the first place

- I keep forgetting doing things on my outpost, because contrary to city, it doesn't remind you to build something there (annoying, especially when there are resources available)

- I keep winning war by "losing" battles: I only defend, and the attrition on the enemy units is atrocious, so after they lose big units to my scout, I win the war. I have no unit left, but still, thanks to some stability or some mechanism, I win, and I manage to vassalize them.

- OTOH, I keep winning wars while losing territories: I am winning aggression battles, but during this time, the enemy AI is ransacking my outposts, and from time to time, I am losing the territory, as another "neutral" AI, I am not at war with, quickly build an outpost on the area, and then it's too late for me to reclaim it again. This is incredible frustrating.

- Vassals of others were ransacking my outpost without me being able to defend without going to war with their liege. OTOH my vassal doesn't seem to defend me in the slightest

I have yet to find the "pace" of this game. I am playing on "normal" difficulty, and in the 2nd or 3rd era so far, suddenly I am outpace in tech and units, and then it quickly goes game over.

I have not tried naval warfare at the moment (the topic this opendev is supposed to focus on) because I find keeping pace on land is difficult enough.

I didn't play the Lucy OpenDev, so maybe I am unlucky and I missed a first "beta" as a tutorial.

Also they are glitches, like if you try to see what a battle is going to be, then the positions of the units for the battle stay on the map even if you decide to go somewhere else, and then your units become "invisible". But hey, not a full game, yet. ;)

    Cat

The game definitely does hold your hand, a bit too tight imo, with tutorials out the gate on nearly everything you do but I understand they still aren't covering everything. Personally I got annoyed how often I had to swat those too windows away. In general you'll learn how the mechanics work after your first playthrough and just refine it from there so it's really not a big deal in the grand scheme of things. More you play any game the more things click or you notice later the tools they provide you what you need to know were always there but perhaps not where you expected to look.

As for luxuries or strategic resources it functions exactly like their older game endless legends which also had no tutorial that I can recall on this. Can build it from anywhere unlike civ series. Just need to own the territory yup.

This being said there is a book icon by your end turn button that when you hover over it it says humankindopedia or something like that will be at launch. Basically a civilopedia, if you've played the civ series, does seem to be in development which is to say what you are looking for will be all in game without having to look into guides or how to's third party.  So.. not in the game yet but it will be!