Chaotic Magic (Major Hermetic Virtue): Flavor text unchanged. When you cast a spontaneous spell, you will need to check for a botch on a roll of 1, in addition to the normal zero. Unlike a normal botch, the Chaotic Magic botch on a roll of 1 will not backfire against you (though it might against your friends). Instead, the spell effects will grow itself out of your control - range, target, and other specifications may be adjusted by the storyguide, but the spell will still be cast.
Notes: The reason my saga is changing this Virtue is because adjudicating it is a pain. It effectively means the caster has a 50/50 chance of the spell going Chaotic. It is a side-effect that comes up not too often, and usually isn't fun because of the math involved. Calculate desired spell, guess at penetration, math your current known bonuses - Oh, are there unknown bonuses or penalties? That sucks. Instead, we wanted the feel of it, but something much easier to adjudicate as a table, and since the spell was probably going wild on a roll of 1 anyway, we just made it a botch risk.
Good Teacher (Minor General Virtue): This does not affect written works. Instead, use the Minor Virtue Great Author, which provides the other half of the bonuses.
Notes: The hermetic book trade is very, very powerful if any of your players get into it. Splitting it up into two separate virtues (Like Good Student and Book Learner already were) balances this out a bit, and lets people still do the part they want to focus on. My saga has talked about this house rule before, in the end we decided not to enact it in our saga, and just agreed to be reasonable with our book production.