After death does person with power of attorney have a moraland legal obligation to family members to inform them of the contents and accountability of funds prior to death?

Yes. The attorney-in-fact should turn over any account information, statements, check books, etc., to the executor or administrator. And yes, you are legally accountable for any funds you spent while you had power over the decedent's estate as their attorney-in-fact. If you are accused of self-dealing then you will need to prove that every expenditure you made while attorney-in-fact was for the sole benefit of the principal. Their death doesn't shield you from accountability. If you refuse to co-operate you can be sued.
Yes. The attorney-in-fact should turn over any account information, statements, check books, etc., to the executor or administrator. And yes, you are legally accountable for any funds you spent while you had power over the decedent's estate as their attorney-in-fact. If you are accused of self-dealing then you will need to prove that every expenditure you made while attorney-in-fact was for the sole benefit of the principal. Their death doesn't shield you from accountability. If you refuse to co-operate you can be sued.