FBX and textures pipeline discussion

I didn’t get any answers to my questions on answerhub so I decide to discuss it here. I’m sure this is complicated topic so it’ll be great to hear your experience. BTW english is not my native language so sorry if I misspell something.
After reading documentation and series of different tests I realize that current FBX pipeline in some way is the same as in Unity but not suitable for UE4. In Unity each material was a link to shader and textures but in UE4 each material is a unique shader. In case if we develop a highly optimized product for mobile platform we need to have as less materials as possible having each mesh to use a material instance instead of unique material. Is it right? If so then we need a way during the material generation (on FBX import) to generate instances of some optimized material with links to textures instead of generating a tons of unique materials. In Unity there was an AssetPostprocessor class that was able to handle such things. Please point me to some solution how to develop such pipeline in UE4. Maybe some kind of plugins will do the job?
The second problem is an art source control and assets import process. What is the best place to store source textures and fbx to be able to modify them in future? For example Artist A created some art and committed it to repo. Then Artist B modify these textures or FBXs and need to automatically reimport this in editor. For me the best way is to store source assets in separate Art folder (psd textures, max or maya models) and export via script from 3ds max/Maya all tga and fbx files in UE4 project folder (where the final assets will be generated automatically). The problem here is:

  1. I need to manually update all the stuff from separate art folder while the project assets handled by SVN integration in UE4. For example such folder in TappyChicken was SourceArt:
    1433318869-clip-5kb-CyhnoHwQZgj8.png
    As far as I understand UE4 will not automatically update it?
  2. If the Artist A by some reason import textures from SourceArt folder with Import button instead of copying it to project folder there will be a problem in Source File Path. If Artist B decide to change that texture on his PC it’ll not reimported automatically because Source File Path may be different for him (Artist A store projects in C:/Projects and Artist B in D:/Work). What it the best solution here?
  3. How to fix auto import problems when I delete by some reason my tga and fbx files in project folder and can’t add them anymore in the same places because UE4 still know something about old and deleted assets?

Please provide as much cases and solutions as possible. Any links, threads, scripts. Thank you!