[dogtown tom]

sfwusc

1. The ability of my family to use the item.

Any person not otherwise prohibited by law can use any NFA firearm regardless of whether the firearm is registered to a trust or individual.

If your Form1 or Form 4 was to an individual, you must be there with them while they use it.
If the F1 or F4 was to a trust, then any person that meets the definition of Responsible Person can be in lawful possession if named in the trust as an RP.
Those persons with the power or authority to direct the management and policies of the trust includes any person who has the capability to exercise such power and possesses, directly or indirectly, the power or authority under any trust instrument, or under State law, to receive, possess, ship, transport, deliver, transfer, or other wise dispose of a firearm for, or on behalf of the trust. Examples of who may be considered a responsible person include settlors/grantors, trustees, partners, members, officers, directors, board members, or owners. An example of who may be excluded from this definition of responsible person is the beneficiary of a trust, if the beneficiary does not have the capability to exercise the enumerated powers or authorities

2. The ability of the item to pass without another tax stamp.

If the NFA firearm was registered to a trust, then the trust maintains lawful possession. It doesn't "pass" to anyone. No tax stamp required.

If it was registered to an individual, then on your death it can transfer tax free to a beneficiary on a Form 5.