Cool. Very cool even. I've seen mention of the moon magic in other comments. I've not read them all, but I think your effects are too weak.Moon effects are supposed to be really powerful and the Night of the Eye was feared by non-mages. And 5E makes it easy: just add or subtract spell levels wityhout affecting the actual spell slot. If your moon is at High Sanction, the spells you cast act as if they were 1 level higher, so a 1st level spell would behave as a 2nd level spell; if your moon is at Low Sanction, you cast spells as if they were 1 level lower. If all three are at High Sanction you cast as if they were 3 levels higher, so a 9th level spell would behave as a 12th level spell; if all moons are at Low Sanction the spells you cast behave as if they were 3 levels lower, so a 9th level spell has the effects of a 6th level spell. A spell reduced to 0th level cannot be cast.
With regards to two moons being at High or Low Sanction, I suggest you do it by school. If your moon is at High or Low Sanction and you are casting a spell of a school under the aegis of one of the other Robes then that spell is affected by the Sanction status of the other moon.