TOBZALP and others, the safety at Broome will increase with D and E above.
From your posts it is clear you do not understand how the FAA NAS procedures work.
Then how would you , CASA does not have an expert in these procedures on staff.
I suggest you ask a FAA Class D controller to explain how the system works , both in a radar and non radar environment.
The Airservices controllers employed in the USA do not want to change the current airspace dimensions or classifications in the Class D environment.
Why not ask your boss for a briefing from them!