Ok so I've only found really old post when googled. Is there an official list of plugins allowed for vanilla community servers? I know admin mods are allowed but is something like automated messages allowed? That doesnt change gui or cui or change game mechanics.

Thanks

See https://umod.org/community/rust/6545-whats-allowed-under-community?page=1#post-1 

The other threads on our site for this are still relevant, Facepunch only allows admin tools.

ok thank you for the quick response are you allow to change the map size? or is it default 3.5k only allowed under community

The size of the maps in Rust are all native to Rust, so whatever Rust can do is allowed.