As for Question #1, the in game help file contains this info but here is a snippet of what you are looking for:
Leveling Up
Each time you reach a new level, you will receive bonus health, energy and stamina from The Godfather. For lower levels, they will be refilled completely, for the higher levels they will receive a maximum of 5000 health, 500 energy and 50 stamina up to your characters maximum.