Righto, the guide itself was not really designed with WoW players in mind because you have many more funky options, with the exception of the Vanilla players out there. That said, it is a good exercise in how a bunch of things tie together, and you can definitely use it for WoW.
However, the problem is going to be in one of two places.
1. The Variable Keystroke assignments per slot of the Character set.
2. The in game binds that match up with the Variable Keystroke Assignments pictured above.
Simply, in the game, when you are on the toon in Slot1 (Lalala). Press F1. Do they target themselves. Yep, all good. No, your in game bind is wrong. Then Press F2. Do they target the toon in Slot2 (Escargoon). Yep, all good, No, update the variable keystroke above to whatever you use to target slot2 (which, in your case, would probably be F3). Keep going through the Target Party Member keys as per the in game bindings, and make sure they match up in the table.
NOW, if you are in fact playing WoW BFA/Classic, you can use the ISBoxer Addon to do the targeting (which I do refer to in the notes, but gloss over how to do it).
First, you need to know the FTL modifiers assigned to each slot.
Write them down, it'l be easier.
Then, in the Click Bar Healing Config, you can remove the Variable Keystrokes, and replace them with a Keystroke Action -> Named World of Warcraft Macro Action.
Where you have a Target Slot 1, you want to replace it with this.
The highlighted items are what I've set. Note, the Add Optional Modifiers, should match the FTL modifers you noted per slot before. So where you want to Target Slot 1, you will use Slot1's FTL modifier set. To Target Slot2, use the FTL modifier set for Slot2 (right shift), and for Slot3, use the Slot3 FTL modifier set (left ctrl).
FINALLY,
For your buffers. You aren't turning off the Buff Bar Key Map in the mouseovers. You are turning off the main healing bar key map. This is wrong.