Both italian (an external consultant suggest us to make a .com web site and terminate the .it but it seem it wasn’t a good strategy and The main problem is that italian .it address has a redirect on the .com, but it’s not work properly.
Hi, google will not ban you for different language sites which are linked to each others. Google might drop the ranking if you use the same text in the same language on different sites without adding a canonical link. So all you need to do is to remove the non-functional redirect from .it to .com.
But to be frank and I am sorry if this sounds harsh: The site needs a complete makeover. It is hard to grasp what you do, it is constantly moving and shifting and it does hurt my eyes. If I were you I would hire a designer to make a new site for you.