Power of Attorney

Can the person appointed to be "Power of Attorney" for someone be challenged?

We are Florida residents and our father resides in Waukesha County in Wisconsin. My husband currently has a sister in Wisconsin has Dad’s power of attorney and is executor of his estate. Dad would like my husband who lives in Florida to also be have power of attorney and be named as executor of his will and estate. Is there any law which would preclude him from doing this as an out of state resident?

I am looking for a simple way to add an attorney-in-fact to existing Durable Power of Attorney. Can a POA executed in 2004 be recorded in 2007? What are the requirements or how can that be done?

MY HUSBAND IS ON A PROPERTY DEED OF A SUMMER CAMP WITH HIS MOM FROM 10 YEARS AGO. HIS MOM IS BECOMING SICK AND HIS NON WORKING SIBLINGS HAVE TALKED HER INTO SEEKING LEGAL HELP TO GET HIS NAME OFF THE DEED SO THE PROPERTY CAN GET SOLD AND THEY CAN GET SOME OF THE MONEY WHEN SHE DIES. WE HAVE TAKEN CARE OF THE CAMP AND HER FOR A VERY LONG TIME BUT THINK HER MENTAL HEALTH IS NOT ALL THERE. WE HAVE ALSO PAID THE TAXES FOR ABOUT 6 YEARS. HE KNOWS IF THEY GO THROUGH ALL HER MONEY THE ONLY THING SHE HAS LEFT IS THE CAMP AND MY HUSBAND LOOKS AT IT AS SECURITY THAT THE GREEDY SIBLINGS CAN'T GET TO IF SHE NEEDED ASSISTED LIVING. HE ALSO HAS POWER OF ATTORNEY BUT THEY ARE CHANGING THAT NOW TOO(TOMORROW). THIS STARTED WHEN HE TOLD HER SHE COULDN'T DRIVE ANYMORE. WHAT NEXT? DO WE HAVE ANY RIGHTS?

What is involved in transferring power of attorney to her daughter?