In my experience with servers, I would advise you to use Valheim Plus and add mods to customize the game to your needs.
At the moment Valheim is more of singleplayer which is grindbased on multiplayer, just without the benefits of multiplayer (if that makes sense, my english is not the best).


I can say that the Valheim map is big enough that 10 people can build several big bases + armor ect without getting into trouble. But, even with a few people you have to quickly drive further and further out for the simplest things (for us tin was a big problem). This can be fun at the beginning, but can also be very quickly just annoying for new people as you can imagine ^^''.
Of course it depends on the people playing on the server.