As I understand the current rules printing, Obscure Magic is not actually cast as other spells but only requires the caster to spend one additional Willpower Point when casting another spell (the obscured spell).
1) Do I understand Obscure Magic correctly?
2) What are the Ingredients listed for Obscure Magic good for, then?
3) To detect an obscured spell, Sense Magic is needed and has to at least match the "Power Level of the Obscure Magic spell" (p. 121) - shouldn't this be the obscured spell's power, if Obscure Magic is not actively cast at all?