I think the policy is explicit with the two exceptions I named.
Does the word "commercial" apply to both filming and still shooting or are "commercial filming" and "still photography" separate concepts to the NPS? In other the words, is the distinction commercial/non-commercial or motion pictures/still photography. That's not discretionary, it's just unclearly worded.
The second area of vagueness is that they may be saying they can charge money for absolutely any activity they decide they need to monitor. That's very discretionary.
I don't see anything else that suggests room for interpretation by reasonable people (yes, I know).
Does the word "commercial" apply to both filming and still shooting or are "commercial filming" and "still photography" separate concepts to the NPS? In other the words, is the distinction commercial/non-commercial or motion pictures/still photography. That's not discretionary, it's just unclearly worded.
The second area of vagueness is that they may be saying they can charge money for absolutely any activity they decide they need to monitor. That's very discretionary.
I don't see anything else that suggests room for interpretation by reasonable people (yes, I know).

