This looks kind like the guide setup. The thing that is missing from your clickbar is that you never call the "GroupHeal Target Slot X" mapped keys. You should set this for each of the buttons in the click bar, in the Mouseover section.
Set the target to self (because you have the actual target set in the mapped keys).
It is also worth pointing out, you are setting targets for the click actions on the buttons. You don't need to. These can just be Window:Current. With your hard set targets, you are asking that slot to runn the mapped key in question and that mapped key then asks GroupHeals (the target) to do something.
i.e. if your active slot was Slot 3, and you pressed the Slot 1 button, then the setup would ask slot 1 to run the SimpleHeal1 mapped key, and then the SimpleHeal1 mapped key would then ask GrouHeals to press SOMEKEY to heal the current target (which is why the mouseover needs to set the target for GroupHeals).
So if you set the target of the buttons to Window:Current, then when you are on slot 3, and click the button, Slot 3 runs the SimpleHeal1 mapped key, which then asks Groupheals to press SOMEKEY. This reduces a small bit of latency because it removes an unnecessary message that isn't needed.