Power of Attorney

If my daughter has a Power of Attorney for health care issues for my wife that has never been notarized, can she sign to have my wife transferred to a nursing home against my will?

Is a Power of attorney in spanish, notarized in Arizona valid in Mexico? Does it need to be filed for every single person individually?

My husband has General Power of Attorney over his fathers finances, i.e. pays his bills etc.. His father has a large credit card bill and my question is: upon his death, will my husband be responsible for paying back the balance? My husband is not listed on the credit card account at all.

A few years ago I was appointed a power of attorney for both health and property for my mother, but would now like to resign as power of attorney and turn it over to my sister, who is listed on the power of attorney document as the alternate power of attorney. To resign, must I do it in writing or can it be done verbally? If I need to do so in writing to make it legal, can I trust an online document I can download for that purpose? If I need a document do I need to have that document notarized or witnessed?

My Power of Attorney says I can delegate any or all of the authority. Is it transferable or assignable? My brother wants (is trying to force) me to give it to him. Is this allowed?