Looks a good trip and plenty of time to enjoy and explore.
Did same trip in 2011 only the other way from Alice to Broome then Middle Lagoon (Magic Place) then Derby and Gibb River road
Only places I didn't see was El Questro and Bungle Bungles.
Will have to put that trip in my diary as I would love to go back as there was so much I didn't see last time.