In the Plugin.yml, if you makes some commands children of myplugin.command, do they actually have to be extensions of it? For example, if you set myplugin.command.hi and myplugin.command.bye as children of myplugin.command, do they have to be used like /command hi or /command bye? Or can they still be used as /hi or /bye? I would like to know this because I don't want to have to set all of the commands in PurePerms Thanks!
They are "permissions", not "commands". Please read the official PocketMine documentation for more information.