"In this case would the separate inherited IRA’s be based upon each beneficiary’s age?"
As I understand it, only for the disabled or chronically ill beneficiaries. RMDs for the other beneficiaries would be based on the age of the oldest beneficiary.
How the sub-trusts would be managed would be subject to the terms of those trusts, and it seems to me that the terms of those trusts would be dictated by terms in the main trust, but I really don't know for sure.
