I think, they halved the effect of guerilla because of those heavy sneak attack bonus damage attacks, because guerilla improves those attacks even more.
The problem with Touch of Frost remains: Its a Hydrosophist Level 10 spells. A Water mage mainly supports or freezes anyway, so I'm not sure, which attacks would really profit from 5% freeze chance.
So really Convection, thought you meant something in direction of zeal/fanatic, flaming passion.
I know, that you meant also damage to magic armor, but it would be still be a bit unreliable. And attacking your self just to get more AP? Such an attack would cost 2 AP aswell, another AP to replenish shield or health, so hardly worth. But cleansing electrified surface can be have tactical purpose aswell. It is surely an idea, that is would bypass the magical armor.
Regarding Made of Stone I think the synergy could be good to make the other talent more appealing.
