1. Weapon ratings on Attack evocations cost 2 shifts for every +1. +0 Weapon rating costs 1 shift. Evocation spray attacks divide by shifts rather than by Weapon rating and Weapon: 0 evocations are allowed. In my experience, evocation attacks are way too powerful; admittedly, the games I'm running are very high-powered.
2. I don't know if this is a house rule or not, but you get an extra stress box for every odd rank in a skill. An actual house rule is that you get an extra mild consequence at +4, and (theoretically) an extra moderate at +8. (Current PC skill cap is +6, but they're facing opponents with +7 skills.)