I don't think Giovinco needs to improve his defensive game, because it might be to the detriment of his attacking style. Messi doesn't track back, and a lot of other creative playes don't go back to help out the defence.
If we have a solid CM pairing, and a stong defense with 2 adequate and competent fullbacks Gio can just focus on attack. That is the real issue that needs to be addressed.
I firmly believe we shouldn't blame injuries and referees. That's what teams like the Dallas Mavericks and Boston Celtics do. We have to overcome all forms of adversity because we are Juve. We have to look within ourselves for the answers.
Gasperini would be my choice, as he knows this club well, has done quite well since leaving our youth setup, and he understands our DNA. I am sure he would do well here, so let's hope Genoa finish 5th