Complicated set-up situation. Help?

[Punainen]

Okay, so I'm a long-time player on the PC. I intend to keep playing on the PC.

But I want my sister (who doesn't live near me at all) to play with me, so I'm going to buy her the game on PS3 and pay for her monthly sub.
But if she ever visits me and still wants to play with me, she would want to use MY PS3. Will she just be able to bring the game and play on her account on my PS3, or would she have to bring her WHOLE PS3 with her to my house to play?

I also considered that during the times she ISN'T playing, I could use that second account to double-box. Would I be able to use the account that's linked to her PS3 to log in on my computer simultaneously with my account?

Will they lock the account for 'suspicious activity' if it logs in in one state at one time and another state at another time?

*EDIT: Also, she has to use PS3 because she doesn't have a PC, but I think she'd prefer the keyboard/mouse controls. Can a keyboard AND mouse be used with the PS3 and with this game?