If you are looking for no griefing use the plugin called Precious Stones. It is very interesting, while you can change what type your land is in. If you want a miner land, place one of the blocks listed in-game and you can make people who visit your island only break the coal of their underground area. A normal land uses a diamond block, and you can block people from even entering, by pushing them back. The Pixelmon server I am staff on, recently changed Factions to PS. Would it work? ^w^
I was playing a little server with my sister once. We kind of have had the same situation! They just kept spawning a million things for us that we don't even need. We then kept getting asked to do mini-games with them. And guess what? They had like 6 admins, and 2 players (us) ON! We quit the server after that. I now only do LAN multiplayer with her so we can do whatever we want, and we can play with mods.