Suggested fix (unconfirmed): Mark the game as private during the checkout process. Alternatively, go to your games list, select manage game, and mark it as private.
The problem
is there a way for me to buy this game... and don't let it show on my profile, or games, or lists?...
Suggested fix (unconfirmed): Redo the park event after getting Roxy to level 3 trust to enable Maya to take time off. Then, visit her at the station to trigger the final event and unlock the achievement.
Irene information can be unlocked by continuing her story, you should naturally unlock it all. For Miu, did you click on the sign in the hospital lobby, the sign on her lab door, and the computer in her lab?