To the best of my knowledge, yes to all of the above.
They currently ONLY sell via Openreach though, no CityFibre based packages but it's in the works apparently.
The connection itself is literally just Vodafone. The PPPoE login credentials are a Vodafone account login. You can use a Vodafone router out of the box with their connection, and the routing and performance were identical between Onestream and Vodafone in my experience.
Billing and customer service are basically the only two things that differ between the two.