As long as he doesn't "overcompensate" - just be himself and not worry about his height. A lot of short guys think they have to do everything to the extreme to compete with tall guys - he's got to get it through his head that is not the measure of a man. His other qualities: intelligence, sense of humor, humility, loyalty, faithfulness, compassion, empathy, etc. are what counts in the long run.
depends on the girl really. if shes a girl who can date a boy with 3 heads all cause his personality then yay those types of girls wouldn't really look a size but if its girls 50% looks and 50% personality then probably not. im sure he'll find the right girl though :)