Removing your ribs would have no affect as far as I can see in your ability to selfsuck. I can selfsuck and I didn't have my ribs removed, as well as thousands of other guys in the same situation.
If someone did get their ribs removed, they'd likely crush their internal organs and die of internal bleeding.
To selfsuck you just need to condition your muscles and ligaments, which is what gymnasts, yoga enthusiasts and dancers do. Most people aren't limber because they don't exercise, it is not because the body isn't capable of such contorsions.