Yes you can, if you are appointed Executor or Administrator of the deceased’s estate.
This is a legal document from the court authorizing someone to take care of the family
member’s business in the event of death.

It depends on the case and what exactly is involved. On the average, High Court cases can take one
to three years.

There is no way to give a fixed amount since this is dependent on the amount of
work involved and the complexity of the case. The best course of action is to consult a lawyer.

Yes, you are the Claimant (as you are bringing the case) therefore, you are required to be present in court unless the matter is settled prior to going to court.