I'd definitely suggest getting him fixed - keeps him out of fights, avoids health problems and scratching (and the marking you mention), and you can never be sure that the females he mates with live with humans who'd appreciate his lineage. Since he goes outside, you might consider getting him a microchip, in case someone's so taken with him that he himself is at risk of being taken...

And definitely, let us see some photos! He sounds gorgeous!

Love, Columbine