You can do the casino multiple times, but everyone ones in awhile it glitches. It has melons, wheat, iron swords, and red stone torches. The purpose of the room is to get the two redstone torches from each side and then use them on the redstone ore block. Then a 3rd dispenser pops out a full iron set and two diamonds. But it's impossible to do this because you can't place redstone torches.
That's the vault. You have to enter a 4 digit code. If you look on the wall behind the buttons it gives you a big clue. Just look at the minecraft wiki and you should be able to figure it out. After that there is a second chest behind the first, you just have to drop down.