I don't know, I haven't seen it. But I believe no. The cocoa butter I mention is the colored cocoa butter. But anyone who has taken his course could shed some light on your questions.
The leftover chocolate is probably in a bowl or something? There will be more heat to get the chocolate out of temper than what you have in your moulds. Regarding the shells/bars - it depends on the temperature you're working with. Bars contains more chocolate and generate more heat when the crystals set, and it might be helpful to put them in a fridge after around 10 minutes, for 10 minutes.
Edit: Better answer above my post. 
