For the house keys, examine the item itself and it will tell you the house that they belong to. It's in Abelleth Village. The gold chests require an item found in Chapter 4. Chapter 4 requires version 4.0 which is currently available to my patrons.
Many thanks for the answer. I would like to take the opportunity to thank you for this great game. I'm a big fan of vampire games and I really like this game. The story, side quest, graphics, pictures, music, etc. is just plain good. I also try to unlock all evil endings so that I get the great pictures. Keep it up :D