Layers and Terrain.
 

If you use layers with terrain will all the layers all take on the terrain. By this I mean will all the layers stretch and skew the tiles or will just the bottom layer do so and the rest of the layers be normal. I don't know how to edit layers in a text document or I would test it myself. Any thoughts or comments on this?

All the layers are stretched/skewed (afaik).

Oh, well that puts a stop to what I wanted to play around with haha.

I have another question about layers, is it at all possible to have npcs behind high terrain? I have tried in the offline editor with no luck but I'd rather be positive before I give up on that.

Nope.