… to avoid confusion and misguiding users
I am not sure this applies here. I am not proposing to change anything about the existing UI, just to offer additional choices. I assume users who find and use the "customize toolbar" feature are also able to understand and use these buttons.
As this is only about additional choices I believe this is orthogonal to bug 1667254.
Probably the encrypt/sign buttons should not be separate: … when encrypting you also really need to sign
At the risk of sounding dumb: Is that true? I understand that it makes most sense to do both, but each one has merits of its own, don't they?
Whatever the reason, I believe this discussion is unrelated: Currently signing is automatically activated when I activate encryption, but I can manually disable it again. This does not change with my patch. It just offers buttons instead of radios/checkboxes in a menu.