That sounds awesome! Elia would delight in the creepy serendipity of it and hang out in the morgue to play with the shadows. But yes, definitely missions. They would be scary together.
As for Blitz, she would have happily flirted back. She's completely shameless, but there's a tall (grumpy) drink of water that I'm sure would have reminded her not to go too far.
xD I don't think any interaction with Nocturne is guaranteed to be pleasant, so that seems totally fair.