We know the original Spock had relationships with humans - there's his past with Leila Kolrami (and the events of the novel Vulcan's Glory
, written by D.C. Fontana herself, where a young Spock has a casual affair with a Vulcan officer). And as for the emotion, this Spock watched his mother die, saw his entire planet destroyed, then experienced Pike's death literally first hand (via mind meld), and then watched his best friend die - all in the space of a year. Old Spock never endured anything
as devastating as that.