Thanks for comments, Everybody!
We definitely spent some time reading up on camping and overlanding in Africa and what we could expect from wild animals. When it comes to lions it seems they are quite uninterested in people (but car tires have been mentioned a few times..). When camping in unfenced camps in the bush we are more worried about elephants, but these creatures also have a tendency to stay away as long as you "where there first" (as in being parked and not driving towards them). We do have a big canister of bear spray (been with us from Canada) and a powerful torch (which doubles as a blunt object), but to be honest I think that if we ever have to use them it we be for two legged animals... Regarding mother nature we just try to be careful. No camping where there are too many elephant tracks, and we try to finish cooking and camp life before dark when we are bush camping. So far so good :-)
37 inch tires makes it a little easier in deep sand, even in 2wd... But I admit I was a little worried when an elephant started chasing us in revers back the way we came from. Fortunately it gave up after about 100 meters and left the road so we could continue out to our campground.