They subtitle Enzo in the US. Punch drunk - nah. Alcoholic - I doubt it. He is quite difficult to understand though. Joe speaks perfectly so you'd expect his Dad to sound a little clearer. But it's part of his 'charm' - he wouldn't be Enzo Calzaghe without it.
Hard to understand? Im 100% scottish & I can understand Enzo Calzaghe. Just thought I would add my tuppenceworth.