I have absolutely NO idea if I translated any of that information properly, but here goes ....
certificato dei carichi pendenti with his mancato versamento IVA is essentially that he was investigated for possible tax fraud. If that is correct, was he ever convicted, has the investigation been completed, was it a favorable outcome?
His casellario giudiziale or Criminal record is clean so he hasn't gotten into any trouble with the police, which would imply that he wasn't convicted of tax fraud or tax evasion. Of course, this presupposes that Italian law works kind of like Canadian law, and I have NO idea.
I am no expert, so I would THINK that if he was not convicted of a crime and only essentially had a tax audit done then it shouldn't be a problem, but a more senior member might know the answer better than I.