Good stuff, don’t hold this back lol.
So is Vision really alive then? I figured he was a figment of her imagination/world she built.
I think he will be. I think somewhere the original Vision's body is being held, but she created the new Vision (like she did her twins) in her world. In the comics, her twins "with" Vision were really just her magic, Vision couldn't be the father. I think the same here, she has created her twins (and Vision) this time. You have to think they want the Vision character back, but couldn't because of the infinity stone that powered him. This allows them to bring him back, along with mutant kids who can be used in a Young Avengers project (that's where Tommy and Billy end up in the comics).
Ejecting Geraldine may have been a part of that. When she gets flung back into the real world out of the bubble, she is wearing her 70s outfit instead of whatever she was wearing if she was in the copter when it got pulled in. That may be a sign that things Wanda create in there can exist outside the bubble in the real world. That would let Vision and the twins exist in the real world as well.
Wanda is really one of the most powerful people in the MCU, and you saw some of that when she started whipping Thanos singlehandedly. It's just a difficult character to manage because she has so much power, that's why her fragile mental state due to her upbringing is important, it kind of caps the character or she could really solve most problems pretty easily.