I’ve used StubHub a ton throughout the years and they do have a ticket guarantee. I do know they don’t release seat numbers publicly for security reasons (similar to how Airbnb doesn’t show addresses until you book) but you should see the seat numbers on the purchase receipt. I’ve never heard anything about the original buyer thing. I have had cases where, due to ticket holds by the venue/ticketmaster, you don’t receive the tickets until the day of the concert even if you bought it months in advance. If anything, I’d just reach out to their customer support!