I did a similar trip from YTYA year before last. Its fantastic.
I just over flew Truscott due to landing fees but the Mitchell Plateau is near by and well worth a 2 night stay to allow a walk into the falls. Good accommodation is available at the APT lodge.
I'd second Cape Leveque. I much prefer it's undeveloped charm over Broome.
I'd also recommend Windjara Gorge not far from Derby. However, to really enjoy this you will need camping gear as there is only a camp ground.
And Kings Canyon Station is good place stop over once you over fly the rock.
You will have a ball!