Complete code rewrite, using another plugin for WorldGuard events and changed config path.
So yeah, I rewrote the entire for better readability.
New plugin for WorldGuard events - I'm now using WorldGuardEvents by Raidstone (
https://www.spigotmc.org/resources/worldguard-events.65176) instead of the other one because I had problems with it.
Changed config path - I changed the path 'borderHopping' to 'allowBorderHopping' so you could understand better what it means. (This means you'll have to adjust it in the config manually if you already have a config)