I did a few days in CPT & JNB in December followed by 2 days at VFA and one more in JNB. A couple of thoughts for you:
1. I don't know anything about this.
2. I would ride in an un-air conditioned taxi for hours before I would ever consider getting on Air Zimbabwe. The 732 that I saw on the tarmac at JNB looked like it had been thru a hail storm. I try not to be shrill about the maintenance of a/c, but there is no way I would get on one like that. If at all possible, take SAA flights. They fly relatively new A320s and provide very professional service. If you book from an agent within South Africa, I undertand that you can get better deals. I sat next to a South African pax that purchased a "vacation" from a travel agent in CPT that included my same flights and my same hotel for about half of what I paid for the flights alone.
3. No. Victoria Falls is one of the great wonders of the world. It would be a shame to get that close but not see it. It is hard to describe the magnitude of the falls. Just do it.
4. I did the Chobe daytrip out of Vic Falls and I would def recommend it. We saw virtually everything except cats in December. I made the mistake of taking the "sunset cruise" on the Zambezi the night before the Chobe trip. What a waste the cruise was in comparison.