I've got two answers, depending on what you mean by "multiplayer server."
MY OWN MULTIPLAYER SERVER.
Where we control all settings and mods, and most importantly, know everyone who joins (a small group of friends).
1A, 2A, 3B, 4C, 5C, 6A, 7C, 8A,
BIG "ALL IN" MULTIPLAYER SERVER
Open to the general public and the great unwashed.
1B, 2A, 3B, 4C, 5C, 6A, 7C, 8B
Actually, my lists are pretty similar, so I'll put it into words.
Own Server: Do what you want. All rules and mods are open to be changed. Few restrictions.
Public Server: Enough controls to prevent griefing (eg land claims), teleports between clan member bases for free, hack prevention (scan for file changes etc).
Let each server determine if it wants to have a style, house rules, enforce classes or not etc.
Not wishing to compare to Minecraft, but . . . comparing to Minecraft . . . one of its great strengths is that it is "many things to many people." Leave things open, and you'll naturally get servers of "builders" - split into "modern builders, medieval builders, pixel art" etc, and "strict RPG", "anything goes" etc.
But that is all dependent on critical mass. If there are rules such as "Thou must finder a Tailor before you can make pants" then you'll turn a niche game into an even more restrictive endeavor.