Yes, letters of intent or term sheets are commonly entered into and they can be either binding or non-binding to both parties. These record the salient terms and conditions on which the parties intend to conclude final agreements, or can be used as the sole record of agreement, in the event that such letter of intent or term sheet is binding.
No. These are usually binding provisions in the term sheet. However, if definitive transaction agreements are concluded, they will typically contain confidentiality provisions.
Good faith is a consideration of public policy. However, it is not a legal rule (unless specifically stated in an agreement). Therefore, good faith is not a requirement under South African law. Parties are free to contract as they want, notwithstanding the fact that a contract may be unfair. Accordingly, unless the contract specifically requires the parties to act in good faith, no contractual damages may be claimed.