Hey! Regarding the addition of an unarmed option, I wouldn’t add it as a new state in the armed state machine, I would add a separate unarmed state machine, this would make things easier, IMO.
Regarding the anim BP preview window, it takes into consideration the default values for the vars, while in-game these values will change in real-time. Unreal’s anim BP has a panel called ‘Anim Preview Editor’ (usually located on the lower right corner), which lets you change the values of each var in real-time for testing in the preview window without changing the default values, which is useful.