Righto,
Follow Me is not broken at all. You are using it incorrectly and assigning hotkeys to the wrong things. There should be no need for you to assign hotkeys to any mapped keys in any keymap other than Base Hotkeys or Combat Broadcast Hotkeys or Custom Hotkeys. I.e. the word Hotkeys is in the name of the Key Map, which is where Hotkeys go.
The hotkey you have assigned to Follow Me should not be used for anything else in your setup, so remove it from all the other places you have assigned or are assigned by default, and make sure you only have the hotkey used once, and on the Base Hotkeys -> Follow Me mapped key.
Second. If you are using the Holy Driver character set, then this is not setup to use the WoW macros for Follow and Assist as you have selected a different targeting option during the Quick Setup Wizard for this team. You can either delete this character set and recreate it, or you can fix the incorrect assignments in the character set under the Virtual Mapped Keys. They should look the same as your "ass" set.

Personally, I think you should consider using File -> Clear and starting again with a clean slate, and just use the defaults for a while until you get the hang of it.