Your comments

Make sure your current render platform is checked in the shader settings. Also make sure that your scene has lighting. If it's a lit shader without any lighting, it probably turns up black. You'll also want to double-check your quality settings, and ensure that you support a few pixel lights
1.06 I think. Download SF using Unity 4, and you will get the latest compatible version
Oh, you want to open it in 4.x after compiling it in 5?
In that case you should remake it in 4.x instead
I'm not really sure what you're asking I'm afraid. You shouldn't have to look at the code at all. Open it in Unity 5.0 with SF, and everything should be alright :)
You need to reopen it in Shader Forge to make it work, it's simply because Unity changed the way their internal functions worked :)
Yep! I'm probably adding built-in support for this later, but in the meantime, you can use this:
http://www.polycount.com/forum/showpost.php?p=2321541&postcount=975