Seriously, just tell the player if they want to do the "Destroy all equipment" thing, the NPCs will start doing it too.
That really is all the solution we'll ever need. I forgot all about "headshot protocol". What a great way to make the runners paranoid and afraid (a very enjoyable state to be in when playing shadowrun).
A good house rule might be that a non elemental damage spell can only effect say spellcasting scores worth of non living targets. If you want to do damage to the surroundings fireball and ball lighting are your best bets.
I love this house rule. Seems like it would be way easier to manage, both balance-wise and just in terms of figuring out exactly what got destroyed. I'd maybe use Intuition for it, to make it an tactic that one can specialize in.
My only real regret in this whole situation has been that I love elemental spells, yet their efficacy in combat stacks up very, very poorly against a powerball.