In the Astral Plane you have Ether.
Fine.
I can spend it on several things like horses or sling shooters Academies.
(Why would sling shooters need Ether by the way, they aren't anaesthesiologists and don't need to sedate their prey that way)

Anyway
So how does it (re)generate?

How much does regenerate every Astra Plane Turn?


I don't want to experiment too much with it as I'm afraid it doesn't regenerate quickly enough

Do you mean Energy?

Your world initially generates 10 points per astral turn. As you expand it by conquering shards, the income increases.

Do not linger too long building up stockpile though, inaction pulls you closer to Chaos.

What does this mean, if you don't spend the energy you get some penalty? Or do you mean if you lose a shard because you didnt want to spend energy, you get chaos?

If you spend too many turns without conquering anything and thus drifting closer to the center of creation, you lose the game. Entirely. Your shard is consumed by Chaos and game is over.