I've noticed the lack of 4th ed munchkin faerie spells in 5th ed, thank goodness, but some were pretty interesting. Does the FoP:Faerie book have some specific Faerie spells for Marinita?
I think with some storyteller permission, Faerie spells could be given a little umph in trade for being created from Faerie Magic.
It seems Faerie Magic is only good for Charms. I really like Charms, but outside of that it seems like a point sink.
As a matter of fact, you can only substitute Magic Theory for Fairy Magic when experimenting or working Faerie magic. So you need to have a Higher Faerie magic then Magic Theory to take advantage of it. Since MT is so very important to a Magus, I don't ever see someone having a higher Faerie magic than MT, so... there isn't a point? I'm going to try it out on my PbP character to see how good charms can get.
RoP: Faerie doesn't have any specific Merinita spells per se, but there are some very interesting Faerie Rites which can be learned by a character who has access to Faerie Methods and Powers most of these use Faerie Magic parameters and could thus be adapted to Hermetic Magic. Some of the powers used by Faeries themselves also make use of the Merinita guidelines and would make great faerie spells...
The advantage of Faerie Magic is that it allows a character to use more Vis/Season at less cost in XP. (eg 3 MT + 3 FM = 60 XP; 6 MT = 105 XP and requires the character to be 35 or older). The advantage to substituting FM for MT is that (despite adding 3 Botch dice) it makes botches less dangerous.
That said, Faerie Magic is a very specialized ability and I suspect most Merinitae never bother learning it unless they belong to a mystery cult and plan to initiate a virtue that benefits from it...