Ps3 – How to deactivate a PSN account on a PS3

At present, there is no way to transfer trophy information from one account to another (still). Logically, it doesn't make sense for trophies to be transferable. This person earned this proof that they did something - what meaning would these have if you could transfer them to someone else? This would certainly allow for a shim to act as a psn id change, but that would be the wrong solution to the problem.

Some few saves and other data can be copied over but often, like trophies, these are usually non-transferable as well. To determine which data can be transferred, you would have to go through each and try it. The logic behind this is probably the same as trophies and possibly even related to how much easier it is to cheat trophies with someone else's saves.

You still cannot change your psn id and there are no practical workarounds. All you can do is start over. Sony might have reasons, but it is a hotly discussed feature that exists on the Japanese PSN. There has never been an outright denial of the future possibility (only statements that implementing this feature is "very technically complex").

On PS4 you can sort of get around this by changing your real name, but that doesn't allow numbers or special characters and will not help you on PS3.

One: You can back up save files and then restore them at a later time even to another account. If you are a PS+ member you can back them up to a server and they will be linked to your PSN. However in your case, you'll probably want to back them up manually, which can be done as so:

1. On the XMB (cross media bar), go to the Game section.
2. Go to Game Saves
3. Put in your memory stick (cf, ms duo, sd)
4. Find the game save you want to copy/backup, highlight it and hit the Triangle button.
5. Choose the menu option to Copy
6. Hit the X button on the memory stick and let it copy.

Source: PS3 : How to backup PS3 game save files to memory stick / sd / cf

It should be noted that some games use copy-prevention methods to, well, prevent copying. However, it's still possible to back even those games up. Google is your friend here.

Two: I'm surprised the previous owner's PSN is still on there, but yes you could use his DLC, as long as his PSN remains registered on the console (so don't delete his User account.) Off the top of my head I don't know how this will affect trophies. You should still be able to earn DLC trophies, but they might register for the owner of the original purchase. (The PS Vita has this problem.)

Three: The PS3 is not region locked for games, so you should be able to play everything fine. However, I do believe the Playstation Store is region based, and so some content will only be available depending on which region's store you access. I'm not sure if this is determined by the console (e.g. a US PS3 vs. a JP PS3) or registered PSN region. Also, you may have some conflict if trying to purchase content that is normally not available in your region.

I hope this helps!

P.S. Congrats on the new PS3!