Yes as long as it is in compliance with the law of that state or jurisdiction.
"Power of attorney" means a written instrument, "Attorney-in-fact" means a person granted authority to act for the Principal in a power of attorney, regardless of whether the person is known as an attorney-in-fact or agent, or by some other term.
Apply to the probate court for the power. If the circumstances warrant it, they can grant that power.
It depends on the State that you live. Some States require that certain provisions be in a power of attorney form as well as having a notary sign the document and other States are more lenient and only require both signatures from Principal and Attorney-in-Fact.
Consult your lawyer.
A power of attorney ceases upon the death of the grantor. For a deceased person, you must be appointed their executor or representative by a court. Generally, if the person had signficant assets or a complex situation this means you need to open an estate, for persons with few assets, most states have a simpler alternative.
A power of attorney represents a living person. After their death, you would apply to be executor of their estate with the probate court.
Unless a power of attorney states a date of termination, the authority of the attorney-in-fact is exercisable notwithstanding any lapse of time since execution of the power of attorney.
They certainly can request it be extinguished. If they are competent to handle their own affairs they apply to the court. If they granted the power of attorney, they can revoke it.
Some states do require the attorney-in-fact to also sign the form.
Executive power of attorney means that an attorney was appointed to handle a will. There are other instances where this can be enforced as well.
A power of attorney can only be granted by a living individual. You want to be appointed executor of the estate, apply to the probate court.
No only the grantor can revoke a power of attorney. That may be the court. And death will terminate the power of attorney.