What documents do you mean? For example, you can get your SIN number right away (and without any problems as far as I know - even if you travel back to Italy). However, to qualify for OHIP, you must LIVE there for 3 months. So I wouldn't land, start the clock for OHIP, go back to Italy for an extended period of time, come back and then expect your OHIP to be covered.
You also need to wait to see if you CoRP has condition 51. That says you need to live with your spouse for 2 years after landing. You can travel for work and for personal reasons for short periods of time, but you can't LIVE in Italy. No one knows how condition 51 will be enforced though. So it may not be an issue. It depends on how much you will be going back and forth for, what the reasons are etc.