My wife and I are flying to Victoria Falls via JNB on Aug 28. It will be British Airway to JNB and than Comair to VAF (we bought the whole set of tickets from BA). The connection time is only 2hr20min (9:05 @TA / 11:25 @TB). Technically it is an "international" connection but the Comair will take off from Terminal B. So practically it seems we need to go through the Customs etc. on the landside, which would be much more time consuming. BA told us that we should get all onward boarding passes all the way to VAF (from Toronto, Canada), and the bags would also tagged from Toronto to VAF. I have the following questions:

1. Do we need to pick up our bags at JNB and re-check them at the recheck counter, or they should automatically be turned over to the Comair flight?
2. I heard that one could pay Bidair who "handles" passenger for quick connections, in our case, is it necessary (2:20 hrs) since it is in the (busy?) morning period?

Many Thanks!