1. I always thought that the bubble technology had to use some kind of scanner to identify a threat. But I don't see the computer freezing time. Maybe she set up an alien artefact somewhere? (and maybe it did activate, but rubble piled on top of it)

2. Yes, because we all know Ianto is a careless idiot, who wouldn't be able to form scheme to, say, infiltrate a secret organisation in order to use its ressources to cure his girlfriend, or be one of 27 survivors out of almost 900... oh, wait...

3. No, I think I understand. Picture it : Green eyes, black hair, always bangs to hide her forehead... She's bloody Harry Potter!