At this point, I am thinking Agatha pulled Peter-Quicksilver out of the multiverse because she needed a body with speed powers, but she could not swing resurrecting the dead even temporarily. I think it could remain an easter egg in that Peter's home universe may never be specified, but the casting indicates where he is from.
As for the TV show angle, I'm still going with that being an artifact of Wanda's subconscious that Agatha can't really stop, so she ran with what she had to work with.
This girl wants to star in a family sitcom? Okay, I can do that - I'll be the director.
There's a bit of Inception-logic going on here where Wanda must feel things are coming from within herself even if she doesn't remember when she thought of it. "Pietro" did some fast talking to reinforce this angle - explaining to Wanda that he showed up because
it must have been Wanda who wanted the kind of disruption he was creating. And she didn't remember wanting that but started to accept it because it fit with how she thought things worked in the Hex.
Agatha's manipulation of Vision is interesting.
If she wanted the hex to last forever, her plan should be for Wanda to stay on her happy life forever. But on episode 3, she pushed Vision to suspect something is wrong with Herb and then with "Geraldine", then Pietro, then revealing he is dead.
Maybe what she wanted was Wanda expending herself, pushing her limits. If she was, say, slowly draining her lifeforce as she maintains the hex, she would be pro-happy life, but she clearly is pro-unhappy marriage.
I get the impression Wanda had to be happy and harmonious to firmly establish the Hex. But Agatha can only control her if she's unhappy and disoriented. Really, it is a skillful and spicy balancing act Agatha is trying to pull off, and it does fit her flamboyant personality (as seen here)
very well. She is clearly sure of herself and her abilities.
