I think it would be wise to spend your time in the central and southerly regions of the parks as this should give you more time to reach the different camps without having to worry about reaching camp closing times. I would suggest that you stay at no more than 7 camps given you an average of 3 nights per camp. Preferably even less than 7 camps as this will save you a lot of packing and unpacking and should still be enough to spend your time in all different kinds of bushveld.
Us personally always mix up safari tents/ bungalows and family cottages during our stay, just to create another environment to sleep in.
It’s hard to help you on the game drive question as I personally don’t like the full day game drives, I would rather drive myself and stop when I want. We always tend to go for the night drives as you get an excellent opportunity to spot lesser common game or spot the cats more active. Maybe Sunrise/Sunset drives? Or even a bush walk. Anyway, we always like to mix it up and see what each surrounding area has to offer before we make an decision on which and how many drives. You can always try and book a last minute activity if you suddenly feel like doing a guided drive, you have time enough anyway
Enjoy your trip and wish you many great sightings.