The things I'm doing:
Magery never gives a skill bonus. Instead there are Magic Talents for separate colleges. These have different costs due to college size - a bit more generous than regular talents, though. Magic Talents can stand in for Magery, i.e. you need either Magery 1 or Talent: Fire Magic 1 to learn Fireball.
Magery and Magic Talent never add their levels when it comes to overcome limits of a spell. Each campaign has a point limit for the combined cost of Magery and all Magic Talents. Magery 0 is 10 points too. So it's much more efficient to max out talents in two colleges and maybe get Magery 0 to pull off impressive things, but you won't be much of a generalist.
There is no cost reduction for high skill alone. Casting cost is reduced by a certain margin of success, but for maintenance costs you need to take a penalty on your roll (which also reduces MoS for casting cost reduction). There are various ways to increase your skill somewhat, but you won't pull off zero maintenance for anything but 1 energy spells without some serious effort.
There are various benefits tied to relative skill level, e.g. the MoS needed for casting cost reduction and the needed ritual. Talent can substitute for points invested in a skill here, but a mage with Fireball at attribute +2 will look very different from one with the spell at attribute -3.
For those interested in the whole system, I put it on my blog:
https://blindmapmaker.wordpress.com/2015/09/06/164/