In the event of an artist/authors death copyrights are treated like any other property in the estate and will be assigned by will or by the probate courts.
Rights are transferable, and generally go to the next of kin unless someone made other arrangements.
The copyright holder, or anyone the copyright holder authorizes.
It would pass to their heirs unless other agreements were made.
the house is paid off and given to the beneficiary
The copyright holder or their appointed representative can take action.
With permission from the copyright holder, yes.
The mortgage obligation remains on the property. If the holder of the mortgage dies then her heirs own the mortgage.
Unless other arrangements were made, the rights would pass to their next of kin.
In writing.
Only use materials in the public domain, for which you are the copyright holder, or for which you have permission from the copyright holder or an exemption in the law.
I believe it reverts back to the owner, and thus becomes part of his estate.
The only way to be certain is to contact the copyright holder yourself.
It seems like you are asking what happens when one joint account holder dies. I believe that most joint bank accounts are set up so that the surviving account holder would have legal possession of the full balance, the same as he did before the death of the other joint account holder.