1) The Burminator
You remember that underwhelming Quality "Elemental Focus" from Hard Targets (p.191, +2 dice to cast your chosen element but drain is turned into that element too and you suffer the side effects)?
That drawback turns out to be a feature if you combine it with Elemental Master (p.36 FA).
Not only is all damage from the chosen element halved, but you also are now immune to the side effects. The kicker is that the damage is halved before you soak.
Suddenly a F12 Fireball is now only a mild 6 drain. If you use a fetish and/or the Mentor's Mask it's only 4.
Well, I can see how it's written in a way that could be interpreted that way, but given there's qualities that grant damage resistance dice that don't affect drain to my knowledge, one could argue that drain isn't really "incoming" damage and wouldn't be affected. Though more likely is that the author of that one simply didn't know that "Elemental Focus" exists. I can see it eliminating the side effects, but I wouldn't build a char around the reduced value lest potential errata wreck the concept before it really gets off the ground.
Independent of it's validity, I believe if you used a fetish it would reduce the drain from 12 to 10, which is then halved, coming out at 5. After all, the Fetish reduces the drain by 2, not grants two automatic hits on the drain resistance test.
You can only have Magic x2 spells known.
At character creation, anyways. And Mastery qualities don't get more expensive afterwards, so you just need to wait a run or two, at worst, before you get all those juicy bonus spells. ^^
The limit might be there mostly to reduce the amount of spells the magician doesn't need to buy formulas for.