Yo saga. I haven’t done much with materials or textures. I’ve been more interested in game logic, physics and python. And I haven’t figured out ipos (f-curves) yet. I use bullet physics and my own maths. I’ve found that I can make objects change color or “fade in and out” using own.color which is a list of r,g,b and alpha and an integer property as a counter. But I can only do this with my material linked to the object rather than a data block. OK that’s one little problem solved. I guess that unless you link a material to an object you can’t access it’s r,g,b and alpha attributes with the methods available to KX_GameObject.
But I still don’t understand what the various capabilities of object linking and data block linking are? And I do use GLSL mode mainly because it gives me more scope and AFAIK has no disadvantages for me.