To address 2 and 4...
2. He's not talking about DoF, he's talking about layering, as in how you'd see in, say, Flash. I suppose enabling a depth thingy would be cool, to be able to see objects through other objects if enabled. It would be tricky to work with, and I think that manual object adding would be better than numbering, but otherwise, neat.
4. Multiple texture layers, each with their own individual color/alpha settings (that's how I interpreted it).