All is not lost, however. There are some really cool ideas for imparting the mood of S&S magic. My favorite, bar none, is Obsession. Once a character learns his first magical Talent, he gains a rating in a new Talent, Obsession. It represents the uncontrollable desire for magical power. From then on, every time the character grows in magical power his Obsession rating increases by one. Any time the character is faced with the opportunity to increase his magical power and the player wants to resist it, a roll must be made. If the roll is failed, the character succumbs. Here is a quote from the Obsession section:
if it possible to sate the character's lust for magic without harming his friends, he will do so. But if injuring or betraying them can't be avoided ... well, sometimes a magician just has to do what he has to do...
I think that is an awesome mechanic to model the absolute danger to a magician's soul. It is one thing to foist certain penalties or limitations on them. If they have the choice of when to risk the dangers, then they aren't nearly as dangerous. When they are being compelled to face the dangers, it changes things.
All in all, there are some excellent ideas here for S&S-style magic, they just aren't very well developed. Something along the lines of Barbarians of Lemuria's magic system would be a good fit. Magic in BoL is a somewhat a la cart affair, but with clear advice on how to judge the power of spells.
It is one thing to embrace the rulings-not-rules, DIY spirit. It is quite another to be left without any direction whatsoever. I just wish there had been a little more in the way of guidance.