Social "weapons" (so to speak) are quite undefendable. Think of a nerd being destroyed by the jocks (via ridicule) or abusive relationships. The only armor is high self esteem or maybe faith as long as you can keep them up.
Maybe you can have a stunt or aspect like some pcsd ex-soldiers disregard for death but there aren't any real defences except being sure of yourself.
This aspect of the "social weapon" concept is quite undefendable beyond a few stout individuals so allowing stunts to strenghten it seems a bit too munchkin to me tbh.
Mental wepons are also similar. Beyond some mundane ones like a vicious tounge, rumor mongering, abuse etc (which are actually fairly long term and slow buildup of social problems ) , nearly all of the mental attacks in the game are magical and they are in direct violatioın of laws (or they are Fae bargain based deals). You can resist them with a diciplined mind but in the books we have seen that if the attacker knows what he is doing (like cowl) it is nearly impossible for even a guy as resilient as Harry to resist.
Although now that I think about it Molly might and will be much more resilient to such things thanks to her understanding of the workings. She needs to toughen up a lot to reliably shrug such attacks but even as insecure as she is, she is probably still better than half the WC.