Nobody. Xabi Alonso won a World Cup winners medal with Spain and on a visit to Ireland he played some Gaelic Football with local children, but did not play for a team and win an All-Ireland medal. This is a common myth that some people still actually believe.
It is Dennis Irwin.
Medal winners do get paid.
No real player. It's probably a fictional player like Roy of the Rovers
Bobby Charlton and Nobby Stiles.
No, the IOC does not pay medal winners.
I can remember two Sir Bobby Charlton, and Noby Stiles.