Ps4 – Migrating game progress to a new psn account

You will need an account on the PS3 that owns those DLCs in order to be able to play those games/use those DLCs (or download them in the first place if you don't have them locally).

You could contact Sony and ask if they can move over the purchases, but I'm not sure if they do this (they definitely don't change PSN IDs).

The easiest way around this is to simply keep that account on the PSN as a user and just set your PS3 to auto-sign in as the new user. The old user account will exist but will basically only be used to validate your DLC/games, so it really won't clutter up anything unless you change users often.

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.