The current guideline on what an attack action is is "Don't be a dick, you know when something is an attack." Treat this as a common sense deffinition not a rules lawyery one.
The diversity of action (for instance recklessly casting a buff spell and shooting a gun) are exactly what the rule is supposed to achieve.
Something can be an attack action at one point, and not at another, but an action prohibition based on intent, rather than capability doesn't make sense. It's not a matter of common sense; it defies common sense that you can only do a certain action when you know it wont hurt anyone, but you can do an equally complex action in its place simply because it doesn't directly hurt someone or something.
Well, I'm glad to know the official ruling, so I can make it clear to the group what the house rules are.
I'll just add it to my proposed house rule list to my group.