If you're hosting a server then one of the
needed mods is
HOSTMOD. The mod adds new options for admins and people who aren't admins alike e.g. You as a server admin/host can change the ability for people to use certain commands like restat etc. You can download
here and there's a thing you can read linked
here for more info on the commands for the mod. For tricks, you'll want
Acrobatics, which allows the player to perform tricks. There's more info on the mod page.