Some PS2 games with online functionality (Burnout 3 comes to mind) are marked copy protected and cannot be moved about. For PS+, you only have to wait 24hrs for redownloading one particular save.
As far as deactivating goes, no way to do it on a user-end without the PS3 operating. You're allowed up to 5 activated PS3/PSPs on your one account anyways, and if you ever cap it for some reason and are not game sharing, Sony customer support should be able to reset activated machines for you.
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