For the first issue, I couldn't reproduce the issue, but I added a check around the offending code that will hopefully fix the issue. If it doesn't, I recommend cycling the selected ammo, or removing and re-adding the character's weapons.
Let me know if the issue still exists.
For the second bit, we don't currently have a way to trigger them manually, since most usage of their combat number is tied to shooting or reactions. I have plans after solo mode to implement a npc creator helper that helps with migrating abbreviated npcs to full mooks. Even the abbreviated hope reborn mooks are setup as full mooks. A little tedious, to implement, but doable. I'll look into adding a roll trigger to the combat number.
Alternatively, it may be possible to just create a move for the combat number, or a new skill.

