This isn't monster hunter where co-op is kind of a joke. This is real co-op where you are always in the same world. You can choose to work together or explore/build on your own and just get together for boss fights. Up to you and your friends how you want to play.

As others have said death penalty isn't all that bad. You can't starve to death but health pool and stamina pool are very important making food a vital item to upgrade. Stamina management is a key factor to survival.

I have made plenty of worlds and characters. With enough experience you can do a no death run from a new seed and fresh character... but learning the game you will die a lot. So I would suggest playing a couple of world seeds with new characters to learn all the mechanics then try a new seed world with a new character and try for a no death run.

It really comes down to how you enjoy a game.
If you are looking for a game to "win" by beating all the bosses then I would suggest you wait until they finish the game in a few years.
If you can enjoy the gameplay loop and enjoy the journey then pick it up now.

The game is open world so how you play it is really up to you.

One other thing... they game will throw hints at you but it won't hold your hand. At times there is almost too much to do and you have to decide where to invest your time. The game won't guide you to every step, so pay attention to the raven and loading screen hints