Do I name my Last Will and Testament as the beneficiary of my insurance/retirement/bank accounts?

If the will created a trust for your children, and it should, then the beneficiary should be 1) primary = spouse and 2) secondary = Trustee of Testamentary Trust per last will and testament. If you have ANY doubt about what you are doing, consult the attorney who drafted the will. If an attorney didn’t draft the will, hire one and be prepared to shred what you have.