I'd replace the +2 Charisma with +1 to lower of Dexterity or Charisma. Hidden Spell is a sound choice. One trick is enough, I would say, Cloaked Casting being my favorite. Double Boost is for Talents. That makes it 3 points. You could add one or two 2-points abilities, like Paired Skills (Spellcasting/Prestidigitation), and Beguiling, even if it's just for the name ...
A master of illusion, shadow and surprise, you are a specialist at catching others unawares with your spells.
Requirement: Sorcery campaign quality
• Bonus Feat: Hidden Spells
• Attribute Training: The lower of your Dexterity or Charisma increases by 1.
• Beguiling: blah
• Cloaked Casting: You gain the Cloaked Casting Trick.
• Paired Skills: When you gain 1 or more ranks in the Spellcasting Skill, you gain an equal number of ranks in the Prestidigitation Skill. You may not increase your Prestidigitation Skill beyond its maximum rank.