How many Stories would be required for it to be considered as a Collection of Short Stories ideally? What would be the approximate Word Count for a Short Story?
Short story lengths can vary widely, and you can do nearly anything you want, but certain lengths are more easily accepted and more easily published. Does this help?
As for how many stories it takes to make a collection, I've got no idea, but some other smart people have given their thoughts here.
Hope that helps!