Soulstones are there to be used. It would be a sad day to lose the game with 8 Stones in your Cache, no? For Lady J, I like to use stones for damage prevention vs Spell damage and Ranged attacks. If she gets hit in melee I like to use them to get an added card-because it is awesome to flop a mask and get Reposte.
Against Raspy (who I play as frequently):
Models I might suggest:
-Stalkers can be helpful, their 6" negative flip bubble can be hard to deal with if they get close enough.
-Sammael loves shooting Rasputina-he has the bonuses for shooting high CA models.
Strategy:
-You need to play with the right amount of terrain, we usually have a lot of cover where I play. That means melee models stay in cover as best you can. Giving Raspy a negative flip to hit you means she can't cheat in a Mask for Overpower nor can she cheat in a high number to avoid using a stone. She could do a focus cast, which is what you want, as it takes up two of her Activations, rather than one.