There are two other things I should mention.

(This is perhaps politically incorrect) The cultural centres are in my view a little bit disappointing. They are a bit kitch and a bit of a tourist trap. So don't necessarily be wedded to going to them.

Also on the way into kakadu (from all directions) there are a number of turnoffs to a lookout/billabong/other. Some are miles off the Highway others are just a few hundred meters. All are signposted and most have distance markers too. Some of these stop offs are hidden gems. So don't necessarily bat along the Highway at 100+ km/h.