Maybe it's because I'm so used to how layers are done in Photoshop and other similar programs, but I believe we should be able to drag the objects in the right toolbar up and down to be able to set their Z position instead of having 11 dedicated layers. Within those layers, you can several objects, all in front of or behind one another. It would just make sense to scrap that notion of layering in favor of a drag-able Z-position.

With the possibility to have so many objects, it can get really annoying when you want one tree to be in front of another, but behind a building of the layer just above it. It would also help with organization greatly.