Does a trustee have to follow the will?

Yes.

A will must be probated in order for it to be approved by the court and for the court to appoint an executor. If a trust is set up in a will (testamentary trust) then the court must officially appoint the trustee also. The executor and the trustee must follow the provisions in the will, the testamentary trust and the state probate laws under the supervision of the court.

Both the executor and the trustee must follow the provisions of the will and the trust set forth in the will exactly. They have no power to change anything. If they fail to act efficiently they should be reported to the court and replaced. They have no other power except that provided by the will and the court.