We think for a 1 week stay, you should allot $3,500 per person.
Fly into Durban, South Africa (King Shaka International Airport).
FlySafair - https://www.flysafair.co.za LIFT - https://www.lift.co.za Airlink - https://www.flyairlink.com/en/za/
Yes & no as any city we recommend being streetwise & not bringing your most prized possessions but overall you should have a wonderful experience & enjoy the people, culture & vibe.
This is at your discretion. We personally do not believe those are needed & have not had issues.
We recommend you stay in Ballito if possible.
Yes - unfortunately you will not be able to only attend the wedding. This is a three day affair.