Questions about how to set curse .eff files, .eff files by class, and charged items that don't vanis

In the middle of a semi-complex project and got stumped. I'm creating a bow inspired by the Eryines in the dnd wikia. https://forgottenrealms.fandom.com/wiki/Erinyes

The bow is a +1 that shoots 1 dmg missle+ 1d6 fire damage in the form of the fireseed projectile for 10 charges without arrows equipped. It can akso cast confusion 1x per day. Ideally it's meant to be used by Blackguards to spread poison + fire dmg to multiple enemies at once but here in lies the problems.

When set to 10 charges at ranged when the bow depletes it's ammo it either vanishes (When the NI variable is set to either "vanish" or "item remains") when drained. When the NI variable is set to recharge after rest after the 10 shots it continues to shoot fireseed amunition without switching into launcher form. Degeating the purpose of setting charges.

Because this item might seem a little overpowered for BGEE It's been restricted from Good and Neutral aligned characters. The thing is I'd like to set a curse that affects non-Blackguard evil wielders of the bow that has a 20-40 chance of causing 4 dmg (fire) + 1d8 (additional fire) per shot to discourage using the bow in any other class.

When setting the .eff to "Use Eff as Curse" then loading a .eff to "Display portrait" (curse) when used by Fighter, FM, etc the curse sign alone shows but the character can unsatisfyingly still switch between weapons. When setting an .eff under "Launcher" and "Ranged" to load a resource file meant to inflict self dmg, as mentioned above nothing happens. Any suggestions would be greatly appreciated.