Fresnel shader and mixed textures

1) Is there anything like a ready made Fresnel shader for Unity? Something that might give that "inner glow" effect of the mashroom in this image (Super Mario Galaxy): http://tinyurl.com/363rhra

Did anyone make it yet? Don't think there's anything similar in the standards assets.

2) How am I to texture a terrain modelled not inside of Unity, with NORMAL MAPS.

To do this, I was thinking of texturing it in my 3D program, by applying different tileable normal+diffuse textures on different polygons of the terrain mesh, with a global alpha for the areas where I apply the normal+diffuse materials.

Therefore: a) Can I apply multiple normal plus diffuse materials to meshes in Unity, so that one material overlays the other only in the areas determined by the alpha channel. How would the normals behave, I wonder. b) Can I apply a single global alpha to a tiled diffuse+normal, or is the tiling a global setting for the material and is there a workaround in that case. c) To apply different materials to different polygons of the mesh, I suppose I have to do this in my 3d application and Unity will import that information - is this correct?

And then, I would like to lightmap all of this.

The intention is of building a home made terrain editor that would allow for tiles to fade to another set of tiles seamlessly. Otherwise, I would have to use a single huge map for my terrain, which would be fine if the terrain is not huge.

I suppose tileable textures with alphas are what they use in 3d game editors nowadays in a similar fashion to the terrain editor in Unity. What I don't like about it is that I can't use normal maps and I cannot use it with any mesh but just a terrain mesh.

Hope that was clear enough.