Agree with keesio. If/when your husband finds out that you landed on the PR visa he sponsored you for, he could report you to immigration stating that you misrepresented yourself at your landing because you did not say that you were already living separately and heading for legal separation a week later. I frankly don't know if immigration would consider revoking your PR because of that. He did sponsor you and he had not tried to withdraw his sponsorship as far as we know. You were however separated when you landed and although you were not yet legally separated, you were heading that way.
You will look a lot better to immigration if you can say that yes, you were living apart because you were having problems but you believed that you would work things out and the separation came from your husbands side and not from you.
The difference is:
1: Person lands on a spouse visa while separated, knowing fully well that the separation is final and will lead to divorce and actually making the separation legal themselves a week later.
OR
2: Person lands on a spouse visa while having maritial problems, separated but not yet believing that the marriage is over, thinking they can still save it. A few months later, their spouse is the one who makes the separation legal.
You see how 1: could be seen as misrepresentation while 2: wouldn't.
Now, what your inlaws did, changing your address by immigration without your knowledge and keeping your COPR from you was definitely not nice and may even have been against some law but that still doesn't give you the right to misrepresent yourself to CIC.
From your first post, you say you knew that your inlaws had your COPR and they may not even have had to change your address as you say the COPR arrived when you were on a trip:
I was away with my spouse visiting my family at the time that they arrived and received the news through my in laws. From that time till recently those papers remained in the hands of my in-laws who insisted to hold on to them until I was ready to go through an entry port...
The direct legal way to deal with the issue would have been to demand your COPR back from your inlaws immediately, threatening police if they did not comply. Instead you waited and waited and eventually you separated and then you decided to get your COPR re-issued.
Getting a PR visa, doesn't give you the irrevocable right to land. If your situation changes, say a skilled worker who gets married to a non-PR/non-citizen or has a baby outside Canada before landing may not land on his visa because his family composition has changed. A dependent child who gets married before landing is no longer a dependent child. In such cases, people who land anyway on that visa have misrepresented themselves and can lose their PR if immigration finds out. Granted you were not legally separated yet so your marriage status had not changed yet at the time you landed. However, if you make the separation legal so soon after landing, it will be obvious to immigration that your marriage was already over and that you knew that. Hence, they could say, you should not have landed on a spouse visa when you knew that it was over.
So does it matter to you if you stay married to him but live separately for a while longer? This is somehow affecting your life? Because frankly, it would be safer for you to leave it for a while.
In my opinion, what you did borders on misrepresentation, but because of your inlaws behaviour, I see you as having some moral rights to do what you did. However, moral rights does not mean they are legal. It's kind of like stealing something back that was stolen from you.
