Thanks for your reply. I was looking for confirmation of my own opinion.
There is a written plan since the Trust will be holding brokerage accounts, and physical assets as well, in some cases. Your are correct that 403(b) plans do not need Trustees, but 403(b)(9) is a unique aminal. Retirement Income Account Plans need aTrust and a Trustee. In this case it operates as a QRP, but is not subject to ERISA.
There is a non-profit corporation which is an Association of Churches. It controls another non-profit corporation which, by State Law, may function as a Church Benefits Board and is authorized to offer, fund, and administer 403(b)(9) church plans. It may also serve as Trustee. The State Banking Commission does not regulate the Trust or Trustee since it is authorized by a specific State Law.
Again, thanks for your confirmation.