This thread is so stupid... the stuff your doing with filemanager isn't anything new lol, the same programs have been around since jailbreaks, people knew the change your avatar they knew the change your psn comment and all that when dongles were around.. and your psn username and password is obviously stored on sony's servers regardless /facepalm
The following user thanked gola for this useful post:
If there was a way to send it to the server like avatar's then yes you could. But there is no way to send your psn name to the server. But with the avatar you can find where the link for each avatar is. And then change one of them to yours that you uploaded. And then go to avatar, and change your avatar to that one.