improved world moderation

customizable roles + other tools for moderation purposes
a setting making that a joining player is put on a wait list where an admin can assign one of base roles "player/guest/admin" and such and also have a "custom option"
where you can freely customize what they can do (something like a list of permissions you turn on or off for them)
can they access chests?
can they pick up items?
can they break blocks?
can they hurt mobs?
and so on and on.
maybe specifically for trading you could also add an option to make a singular chest "tradable" meaning that said person can access it, alternatively make it a separate item you can make.
having an admin menu with commands for managing your world for example
-giving the "guest" component to chests/workbenches/other utilities
-selecting an area the guest cant leave
-selecting an area where guest can mine blocks (if they cant mine blocks by default)
and so on.

TLDR
moderation settings and tools to avoid griefing attempts.