Surely a sky sub for xbox will carry standard freeview channels
No. Sky and Freeview are different companies entirely. It's not even the full Sky lineup (No Sky One for example).
The listing (as far as I can find out) is G.O.L.D., Sky Real Lives, Sky Arts 1, MTV ONE, Sky Sports News, British Eurosport, ESPN Classic, Sky News, National Geographic, Nat Geo Wild, History, Eden, Cartoon Network, Boomerang, Nickelodeon, Disney Channel, Nick Jr, Sky Sports 1, Sky Sports 2, Sky Sports 3, Sky Sports XTRA.
The BBC wanted to do an iplayer for xbox but Microsoft wouldn't let them do it unless they limited it to gold subscribers, which the BBC were unwilling to do so it never happened. You can, however, stream the match via your PC.