Secret Caster:
a Dawnflower dissident can disguise his spellcasting with a Bluff check (for spells with verbal components), opposed by the observer's Sense Motive check, and/or a Sleight of Hand check (for spells with somatic components), opposed by the observer's Perception check.
Secret Signs:
Let us for the sake of argument say you are using both of these abilities. Would they overlap when it comes to the Sleight of Hands check? Or do you get to make two? And does the same apply to the observers' Perception checks? If you cast a spell that has only somatic components, an observer must make a Perception check opposed by your Sleight of Hand check to notice your spellcasting