UV mapping multiple textures

[micheus]

Hi krisk78
I'm away from my PC, so I cannot help much by now.

But, this sounds strange:

I also can't find any way to define texture scale or tiling when using regular materials without AutoUV.

The AutoUV editor is used to set the UV mapping information to the selected mesh. This "without AutoUV" means what exactly?

We can assign any material to a mesh. If that material has a base colour texture and the mesh is UV mapped, you are going to see that texture applied to the mesh. If not, that texture will mean nothing for it and it will not be shown.

Without an screenshot or more details about your materials, meshes it's complicated to evaluate and suggest something. I may spend time talking about something that is not what you really want/need to know.

Usually we have a UV mapping group (islands) for one texture space [0..1,0..1] (tile). It seems you have "broken" the objects mesh in three parts (groups).
But, I don't want to go further without knowing what you have in mind.