It's the same difference between a gray fox and a fox in general. Gods are not unproven, just ludicrous.
I don't see how. A "fox" is still something that has a definition, even though there are subcategories beneath it of "red fox", "grey fox" and all the other kinds of foxes. There are specific properties which an entity must have to be correctly called a fox and you can check those properties against the definition. For instance, if something has leaves and gets its energy through photosynthesis, then that something isn't a fox.
When you get to gods, there are those which have a definition and one can easily be a strong atheist in regards to because the properties which make up those definitions don't exist and you have those gods which aren't even defined in the first place and ... they just aren't defined. They're nonsense statements.