Hmm... So...

Let's see, I have three different accounts in the Ps3 (Not PSN accounts, managements account, with different storage of the games and saved data, etc)

I could use the same account of PS3, changing the PSN and then it would link my SE account to that PSN, isn't it?

So if I change the PSN to one I make, I can login in the game with my account. If she wants to play she has to login with her PSN and then her SE account and so on.

Linking an account that started in PC to PS3 won't make me unavailable to return PC, isn't it?