With reference to Little Wing..out of pure "theoretical" curiosity (don't worry it won't affect how I play it )

I note a lot of people (forums, "teachers on vids" etc) stating this song is in the "key" of Em - I can see how this is a simple explanation.

Could it actually be considered G Mixolydian? (based on the FMaj chord?)

Is there a "name" for a minor progression that has a flat II? IE a relative minor of mixolydian?

Please be gentle.