I've done a full rundown on Episode 8, but in case you want the real meat and potatoes I've broken my 5 key thoughts, takeaways, and predictions down right here.
1. Wanda is a mutant – not mutated. In other words, she was born with her powers and the Mind Stone only amplified them. We know this because it's implied that she used a probability hex to keep the Stark missile from exploding – so she was either born with her powers or Chthon touched her with them (see below). In either case it makes sense to go this route to explain why not everyone becomes a mutant if the hex expands to cover the planet or more.
2. The end exchange between Agatha and Wanda suggests that Agatha is realizing that Chaos Magic is real and that Wanda is the mythical Scarlet Witch touched my Chthon – who wrote the Darkhold before being cast out of earth in hopes of finding a vessel to return through one day. On realizing this, given Agatha's interest in dark magic, I think she might try to use Wanda to get to Chthon. Especially since she seems to think that this magic is wasted on Wanda. She mocks her for using it to make “breakfast for dinner” – a callback to Episode 1.
3. The Vision inside the hex is fabricated. Hayward still has the real one and orchestrated everything to try to get him “online” (as he would say) again – suggesting again and again if she was sure she didn't want to use her power to bring him back instead of burying him. I think he planted the deed that was the final straw in her car to get her to go to Westview and cast the hex. If you look at the Grantees on the deed, they are Wanda Maximoff and “The Vision”. That's what Hayward calls him. Not what he calls himself. But even if he didn't plant the deed, he pushed her over the edge when she tried to collect Vision's body. Then blatantly lied to the group later when he presented the footage and claimed that she'd stolen Vision.
4. The Vision that Hayward wakes up is White Vision. I think the final showdown will include a fight between Red Vision and White Vision and that the actor that Bettany was talking about was…himself. Think about how he talked about having fireworks on the set with a guy he'd always wanted to work with. This is totally his sense of humor.
5. From the way Agatha was talking at the end, I don't think the twins are real. I think that that loss in the end – along with the loss of her Vision – is going to be the thing that puts her over the edge to the final hex expansion.