Hi David
You are doing a lot in a very short time so my comments reflect that:
One night in
Katherine is probably enough.
Suggest you spend a lot more time in
Kakadu - do the round trip, don't miss Obiri, Gunlom, etc
Perhaps 2 nights in Adels Grove and 1 night in Kingfisher
Camp (on the way to Hells
gate - the road was very good last year when I did it).
Don't miss
Barcaldine and the tree of knowledge, it is spectacular.
Butterfly Springs is good but a long way out of the way for a short trip - eg. need a day to get to the fishing spots.
Lost City is
well worth a visit.
Your recovery gear appears good and you definitely do NOT need a winch - I have one and have never needed it, even on much more extreme tracks.
Have a safe trip. Remember, it is better to miss something, when you are enjoying being where you are! You cannot possible see it all.
Cheers, Dalb