You need to speak to a local attorney. While I do not practice in your state, much of what you have related would be complelely contrary to the responsibilities of an executor of an estate. An executor has the highest duties toward the estate and its beneficiaries TO STRICTLY ADHERE TO THE PROVISIONS OF THE WILL and the laws of the state, and paying him or herself out of estate assets at the expense of the beneficiaries is completely improper, as is modifiying the distribution from what the will provides. If your state has similar law, there are many things that can be done.
Executors are entitled to be paid for their work, which would come out of estate assets, but not to require third parties to pay estate bills to leave more in the estate for the executor to pay to him or herself.
In the states where I practice, the beneficiary is entitled to see the records, and if he or she refuses, if request is made to the court, the court will require it.
Please get to an attorney immediately who practices probate law in the state where your mother in law lived.