So we have shields right now that give you a damage bonus, or an ASI bonus, so why not extend that a little?
For example, have a "Toxic Sharpshooter Shield" shield that would give "Handgun: good chance of causing moderate poison" combined with "Handgun Damage Penalty: Med". With this shield equipped, you'd be able to, say, poison gremlins with your callahan or umbra shots with a similar damage tradeoff to what an actual poison version of these weapons would give.
Could have a few different statuses for guns and swords in turn. Bombs are probably best left out given the vaporizer series has different status mechanics compared to other weapons.
Would the decrease in damage be equal to equivalent counterparts that deal status? Like how alchemers lose ~20% damage in order to deal status.
Personally I feel that it would need a bigger damage decrease than that, because of the possibility of dealing double status.
I'm interested in seeing what happens when a blitz deals stun 3-4 times during a vana mace animation... Speaking of which, having a freezing blitz/plague would seem to make vana solos easier.