wow, so many question! I know these:
new girls are in shop chest (5%chance to get new one) or event or at shop (should pay money)
about packs, they have series of card (rare pack have rare cards, not all of them!, mythic pack have mythic cards) and you have to choose one of them (if they are same to you, pick the one whichhave greater number)and yes, It has lake of information about which cards to choose and number of theme