Power of Attorney

My handicapped son has turned 18. He has gone to live with Dad and so Dad is getting a limited conservator ship. They reside in Palo Alto California, I live in Duluth Minnesota. I will need a Medical Power of Attorney I am told, in order to continue having input and access to Alex's medical and Dental records and needs. Can I just get a Medical Power of Attorney form and we sign it and that's that?

How do I relinquish my mother as my power of attorney if she lives in Indiana and give the power of attorney to my girlfriend who I have now lived with for over a year?

Does person (agent) holding 'power of attorney' assume any liablity or responsibility for outstanding liabilities of the 'maker/principal' after all assets and real estate of principal real estate are properly disposed of/sold by the 'agent'?

My Grandmother has a power of attorney over my Grandfather and she was wanting to know if this will still be in effect even after the death of him? If not he has children that would try to get everything that they could. If him and her wanted everything to go to her after his deaath what would they need to do or is this possible. Also he has alzheimers and I dont think that a will has been done. Is there a legal way for all of this to be less of a burden on my grandmother and for her to get all of their assets?

my brother was given poa. what criteria would i need to contest this as there are obvious financial irregularities and he refuses to provide details. The parents' money bought a house, motorhome, etc. with a view to take care of them in exchange. their entire life's assets were (reported in medicaid application) to be exhausted and the folks on medicaid and put in a home within a nine month period. he also has blocked me from access to my parents' medical and care information.