1: In order to unlock that chest you have to have taken Tom's ring finger, shown it to the guard just inside the front door of Luxurious' House, he unlocks the door to the private chamber, you have a nice lil chat with freak-boy, he unlocks the chest, and then you get to kill him.
2: Since you have pressed all 3 buttons in the private chamber the barrier in the house should be down. Its just a bedroom with a chest in it. I dont think there is anything of importance in it though.
