How can there be anything other than a formal accounting? Someone has to add up all the assets, pay the liabilities, and distribute the remainder in accordance with the will and/or state law. You take all the bank statements, and financial account statements, and whatever else there is and it should take half an hour or less.
The lawyers request for indemnification seems unusual and out of line to me. Who is the executor? That’s who is in charge. Does anyone have any idea of the order of magnitude of the assets?