Not entirely true, some games that are labelled "PSN Game" have a physical release, I know for sure that Pure Pool does.
Very true. There's also cases where some regions only get a digital release, but others get a physical one. Just going by the first page of PSN games, I believe Little Witch Academia is only getting a digital release in the states, where it's both in Japan. Owlboy is also listed as PSN game, but it also has a physical release.
I'm pretty sure Sony is counting any and all full game releases in their ratio.