Is this game ok to start now, or is it recommended to wait for the final release?
It's already got a TON of content, so you can go ahead and start. You might want to keep links to the two available guides (in this thread) handy as there's very little guidance within the game itself (lots of guesswork). Once you get used to the game's mechanics though it gets really, really fun
Also, it's pretty much a sandbox game, so you can do a lot of stuff (exploring, fighting raids, building bases, etc.) while you wait for updates. Though it'll probably take you quite a while to get through all the story quests already available.