What are my rights to securing Father''s POA/Exec of Estate''s acctg records of Father (Trust in POA/EE''s name; no Trust in Father''s name)? Thank you.

It depends on the circumstances surrounding the creation of the trust and the trust language itself.  Assuming your father had the capacity to create the trust in 2009 and there was no undue influence on behalf of your sibling, I would then move to the language of the trust.  If the trust gives your sibling the authority to do what he is doing, then I don't know that you have any particular remedy as his heir to challenge this.   I also don't know why your sibling would have any legal obligation to provide receipts to you unless you are a current beneficiary of the trust.  Would your father have to provide you receipts for what he was choosing to spend his money on?  No.    Having said the above, this all goes out the window if there is elder abuse that is occurring.  If you truly believe that your sibling is exercising undue influence over your father with respect to his finances or that he didn't have the mental capacity to create the original trust, you can certainly contact the MO Department of Health and Senior Services to file a claim for elder abuse as well as file a claim in civil court contemporaneously with an action to have a guardian/conservator appointed for your father.  I think that that is an absolute last resort as there are a number of issues with guardianship/conservatorship that might actually make the current situation preferable.   But remember, if you believe that your father did not or does not have capacity, the court's presumption is that your father has capacity and you will have the burden of proving that he does not.  I would be very hesitant to exercise this option unless and until you consult with an elder law attorney who can more closely examine the merits of your case.