Bit problem I have with the Quicken Willmaker is not really know who is the best person for a co-trustee/etc that you need to include on it. It doesn't allow the co-trustee to be a beneficiary. It's also not setup to easily let you create a trust called 'drumenigma RKBA' if you so desired something other than your name as the name of the trust.
I hate to be pedantic (though, perhaps, I do not hate it enough not to do it), but you prove my point:
1) If your software "requires" a co-trustee, it is defective from the gate, as there is nothing in Massachusetts law that requires every inter vivos trust to have a co-trustee. And while the law of every state is different on the general subject of inter vivos trusts (another problem that generic software doesn't address), I'm not aware of any jusisdiction that requires a co-trustee on a garden variety inter vivos trust.
Which is not to say that a well-drawn trust instrument should not deal with the questions of vacancy and succession. As a practica matter, if the only nominated trustee dies, resigns or otherwise becomes unable to act, most likely a receiver will be appointed to administer the property held by the former trustee in trust (known as the trust "res"). Receiverships cost money (generally, a healthy chunk of it), and so the first thing the Court is likely to do is to order that some of the trust res be liquidated (read: sold in a public sale) in order to fund the costs of the receivership.
2) The software doesn't make it possible (or easy) to give the trust a name. I, of course, don't know for a fact, but it is remotely possible that this is so because trust "names" are meanningless. A trust, unlike a corporation, is not a legal person. A trust cannot own property, sue or be sued, make a deed, or do any of the other legal acts that legal persons (i.e., but natural persons and corporations) can do. A trust, rather, is a separation of legal title and equitable title, so that the trustee has bare legal title to property in which he has no personal interest, and which he is bound to manage for the benefit of the beneficiary or beneficiaries. The trustee is subject to a raft of duties, including the duty of fealty (loyalty), the duty of diligance, the duty of productivity, and the duty of diversity. (The economic sort, not the ethnic sort.) This collection of legally enforceable duties, by the way, is generally not understood by most non-professional trustees, a fact that usually brings them great grief (and the bar some measure of wealth).
Now, I should disclose that I have never taken the time to research or ponder the question of how an inter vivos trust might be used in connection with taking title to a National Firearms Act firearm. But the first notion to get out of your head is that
the trust would be the owner of the firearm. As I've said, a "trust" does not exist and cannot own property. As a result, the NFA firearm would be owned, legally, by the trustee and it would be owned, equitably, by the beneficiary or beneficiaries. At the risk of speculating, I would expect that both must be demonstrated to be qualified owners, and most likely both would have to be identified on any registration required for the firearm. So I guess I don't really see the point.
3) "It doesn't allow a co-trustee to be a beneficiary." Wow, what a can of worms. In the first place, it is difficult, and in some cases impossible, to square the fiduciary duties of a trustee from the personal interest of a beneficiaries. And where you have the same person as the sole trustee and the sole beneficiary, you have a trust that violates the Statute of Uses (chapter 2 of the Acts of Queen Anne, which is still the law in Massachusetts and a lot of other places), the result of which is that the trust is a nullity and will be ignored.
Now, it is possible that you may be getting the impression that you are about to jump into a pool that is way over your head. If so, then my mission has been accomplished.
I hope I can say this without causing offense, because I really mean to be helpful, but the notion of a layman using a piece of computer software to draft a legal document of potentially huge consequences makes about as much sense as a fellow figuring that, since he has a sharp knife, he can remove his own appendix.