It is certainly possible to withdraw from the duties. The court will appoint someone else to serve.
That depends on the wording of the will. Being executor does not automatically give you a right to the estate.
You really don't need to do anything because you aren't the executor yet. If your mother dooesn't change her will before she dies then at that time you can file a declination with the court as the named executor. The court will appoint someone else.
The court will appoint an executor either an attorney or a bank. The cost will come out of the estate.
Anyone can withdraw from being an heir. There is no requirement to accept an inheritance.
Yes.
The executor is entitled to compensation as proscribed by the will or the law. The relationship of the executor to the decedent does not matter.
There are no residency requirements for being executor. The beneficiaries do have to be citizens of the US.
The executor of the estate is responsible for executing the will. They will have to get the will eventually. The decedent, being dead, cannot very well object to their seeing it.
They can't claim to be the executor, they have to be appointed by the court, otherwise they have no legal standing to do anything with the estate. And you have the right to object to their being appointed executor.
The beneficiaries' estate will get their share. The executor will continue to process things according to the will.
It depends on the laws of the particular state where the will is being executed concerning the executor.
Being the executor does not make you personally responsible. The estate has to pay any debts. If the estate cannot pay them, the debtors do not get paid.