I found two problems: When I hit an enderman it teleports away and doesn't come back. Second problem: When I destroy a block it may not drop! I already lost 4 diamonds for example. (Minecraft ps3 edition)
If it is daybreak or daylight then yes enderman will teleport and not return.
Floating blocks is a new problem in the game. I've seen them float up through 5 layers. Stay closer (no more then 1 block gap between you and the material) to whatever you are mining particularly diamonds or whatever else is important to you.