Where this is
Early alpha, and honest about it. Forty isles, four resources, five buildings, live multiplayer, and a world that keeps running when you close the game.
Territory, host against host fighting, skills, gear, sieges, a market and hand to hand trading have all landed. Crafting, seasons and the nine heroes have not. Come in at this stage and you will watch the thing take shape, and what you say about it will change what gets made.
The alpha gets wiped when the beta starts
Every isle, every stockpile, every banner planted in the alpha goes away the day the beta opens, and everybody starts again from nothing on the same morning. A Rust wipe, announced well ahead of time rather than sprung on you.
This is worth being exact about, because the game makes a promise that sounds like the opposite. Your work is never erased is a rule about the world: nobody can raid your home isle, nothing decays while you sleep, no other player can take what you built. It has never been a promise about the alpha itself. The alpha is friends and family finding out what is broken; the beta is the real run, and it deserves to start on clean ground rather than on a world shaped by a fortnight of bugs.
So build like it is a sandbox, because it is one. What survives the wipe is what you told us — and that is the part we actually need.