Hi everyone. I'm a newbie here and am looking for advice on an issue I am having with automating a series of actions to build up metadata on unique images. More specifically, I want to create a set of separate actions that will:
First action will import a previously created .xmp metadata template that enters a basic description and base list of keywords
Subsequent actions will import additional templates I have set up with very specific keyword sets and append additional keywords to the previously entered list.

For instance, say I have a photo of a mixed small breed dog that is sitting up and begging. I would like to be able to display my actions in button mode and just press a series of buttons to gradually build up the keyword list, similar to the following:

Action 1 would be to enter common metadata for a specific type of broad category such as "Dog" - This would add my a basic description, copyright info and some general keywords like "dog, canine, pet, domestic, pup"
Then run action 2 named "Mixed Breed" which appends more keywords to the existing list such as "crossbreed, mixed, mutt, mongrel"
Then run action 3 named "Small Breed"  which appends evern more keywords such as "small. little, lap-dog, toy"
Then run action 4 named "Begging" which finishes off my list with more keywords such as "beg, up, asking"

The issue I am running into is that when I record each action, PS is not recording the action of importing a selected keyword template and appending the new properties. Instead, it records the list of keywords that were inserted by the template that I just imported and wipes out any previously inserted keywords. It does not seem to be registering the step I am taking to select "Keep original metadata, but append matching properties from template" then press OK on the dialog box that comes up. The action records with the step description = "Set file info of current document" and the keywords entered by any previously run action get wiped out and replaced by the import of the template of the next set of keywords.

Does any one know of a simple solution to record the step of appending the new keywords instead of replacing them? I have a feeling there is a way to do this through the Script Events Manager but I do not know write code. I am just looking to see if there is a simple step I may be missing in the action recording process. 

Thank you in advance for your assistance.