Required equipment

Hello everyone!
I want to implement ranged weapons into my game in the same way that FFXII uses them; meaning that if your character equips a ranged weapon (gun, bow, crossbow, etc.) he has to equip ammo for it. The ammo won't be used up.

Currently I have it working like this:

• Equipping a ranged weapon grants a trait that allows to equip the correct ammo (bows allow arrows, crossbows allow bolts, etc.)
• Using Yanfly's Equip Core plugin I have locked equipment slots 1 & 2 (main hand & off-hand) which makes it so you can't unequip either weapons or off-hand armor (minor problem: other characters can't unequip their off-hand items)
  
• If you change the weapon to a different type, you lose the trait and unequip the ammo, gaining the trait for the new weapon. But you can leave the menu without ever equiping ammo, which I don't want.

My first try for a workaround was to have a parallel event running that checks which type of ranged weapon the character is using and equip the default ammo, but since the character hasn't got the trait to equip ammo in the databank I can't choose ammo to equip.

Current workaround checks which type of ranged weapon the character is using and if any type of correct ammo is equipped. If not, it shows a little message and opens the equipment menu again, but that's not quite as ellegant as I want it to be.

Any help would be appreciated!

EDIT: Made a small video showcasing how it should work.
[embedded media]

Maybe another way to do this would be to use Yanfly's Skill Cost Items plugin http://yanfly.moe/2015/12/12/yep-43-skill-cost-items/? Each use of a skill (say, fire gun) would use up any number of any itemp you whish (as bullets for a gun).

I'm not sure how to do this specifically, and you might have to go lunatic if you want to use the default attack skill with that option. If not, you'd have to set different skills to use different weapons, but there is definitely a way to do set different skills as default... using some other Yanfly plugin I can't remember right now.

I know I can use items as cost for skills, but that's not what I'm looking for. What I want is that equipping certain weapons forces you to equip an off-hand item from a specific list, and without doing so you can't leave the equipment screen. The ammo in this case would work effectively like a shield, but instead of raising defense or evasion, it would grant bonus atk, states, or elements to your attack and would not be consumed.

Ok, sorry for the misunderstanding. I'm not aware of any plugin that would allow that for now. I guess you would have to go lunatic, which is uncharted territory for me...