What are some situations that indicate reasons to seek counsel on challenging the behavior of my Dad's POA?

My father is 87 and has advanced cognitive degeneration, perhaps Alzheimers. 7 yrs ago he told us he designation my sister as medical POA and myself a Executor of his will. He lives alone and his care is under the juridication of my sister. Her behavior suggests the possibility that she isn't acting in his interest and may be beyond the scope of her rights as POA. I understand that such issues are complex, so I'm really only looking for an 'informed impression' as to wheter it makes sense to speak to an attorney. Here are some illustrative situations that have caused my concern:

. I learned my sister had my father's will changed around 7 years ago when my father's condition wasn't as chronic. I saw a letter from her attorney saying he'd prefer not to be involved, as it constituted a conflict of interest. As asked my sister to see the changes but she has refused. My father has expressed continued anxiety, in writing, about any changes to his will that impact his wish to have his estate shared equally by his children.
(I understand I can't request a copy of his will from whomever changed it. I live on the opposite coast, but can I have my father sign authorization to release his will to me?)

. when my father has had to go to the hospital, SHE (my sister) has instructed doctors and nurses not to discuss his condition with family members.

. She has denied access into his home to other family members -- e.g. changing locks.

. She has 'informed everyone' that no one except her family is allowed to spend the night with my father.

. She has declared my sister as "estranged" from the family and claims that whenever my father sees her he becomes so anxious that they've had to take him to the emergency room. My father routinely discusses and demonstrates enjoying this sister's company.

. She has said that her husband has been designated Financial Power of Attorney yet will not produce any documents. When my father is questioned about this, he responds in a nebulous state of confusion

. I believe that she has been paying herself and her husband for services, which I appreciate can be appropriate, but will not provide the POA document to validate any such arrangements

. She insists on not selling my father's (expensive) car because it would upset him. He has not driven for more than 3 years. She has refused access to the car for family at times when their car was in repair, yet lets his caregiver use it at will

. She has moved 3,000 miles from my father but insists her hired help allows her to oversee my fathers care. It's generally questionable whether he should live alone -- for example, the condo association questioned his safety when he left a burner on, causing a small fire. My sister insists he is fully capabile of living alone with the 20 hrs of weekly companion coverage.

. There are also some bizarre situations. New boxes of condoms have been found in his drawer. He cannot leave his condo unassisted, so it raises some fair concerns about the circumstances in which these are being brought into his home.

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So, again, I am looking for an informed impressions on how to proceed. Assuming these situations are true, do they constitue potential abuses of POA authority, or issues that sound like they would get counsel on how to proceed in my father's interest?

Another perhaps simpler area of advise would be generally wheter I have any right to see my father's legal documents: his will, the POA documents, etc, and how I would best exercise those rights.

Thanks!

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