A little egg on my face 
I have avoided Familiars in 5th edition, so when I read the rules last night I was confused. The powers instilled, they can only affect the magus or the familiar? No granting the familiar the power to trun people to stone with its gaze or to breath fire?
You sure can, but it'll be a MuCo or MuAn effect that grants the ability to produce the effect you desire, rather than simply the spell that produces that effect.
Note though that with an appropriate MuVi effect, you could probably a fire-breathing familiar give that power to the magus, as it used to be possible with bond qualities.