but are there any actual rules/rulings to back up that reading?

Nothing I know of. The only thing that comes close is when you have optional abilities. Like say on R7-T1 where you can do one or the other, or both of the options.

But the whole thing is considered one action. The paragraph doesn't change what is part of the action. Everything listed on the card is part of the action, even if it's optional or for some reason doesn't apply.