“whose” (line 14) can be replaced by which or that.

“safaris” (line 10) is in inverted commas to signal that there are no real safaris in Zimbabwe anymore for the local tourist authorities have banned them because they regard them as politically incorrect.

if “has become” (line 2) is replaced by became, no change whatsoever in meaning will take place in the sentence.

“for scuba-diving” (lines 6 and 7) can be replaced by in order to scuba dive.

“must” (line 19) expresses the notions of desirability or advisability.