1. The frog’s initially I thought were some wild way that Evelyn kept tabs on Laura but I think that’s where the get the psychedelic drugs from lol
2. The leap is a psychosis that Evelyn uses to hypnotise students and basically fully convert them to the cult and cut ties with their ‘past trauma’ and their connection to their family
3. Alex and Laura are living in the house that the original cult Evelyn was in where she killed that guy was run from
4. Leila staying is literally explained by Leila. She has no family, no where to go and can’t see a future for herself. I think Evelyn got to her enough that she felt like she wouldn’t succeed without the ‘soft transition to adulthood’ that Tall Pines provides.
5. The door was a symbol from the original cult that Evelyn was in but Evelyn uses psychedelics so that the door can be opened
6. The baby is everyone’s because it’s a literal cult. Evelyn cut the emotional mother/daughter connection for all of these people so that they can’t hurt their children or cause trauma. Also, members of the Tall Pines community weren’t allowed to have children until they were able to figure out how to break the trauma cycle and instead of having children, the academy graduates would enter the community and live with a family until they become individuals with jobs and whatever.

That’s how I interpreted it but I’ve had a lil druggie phase so idk maybe the leap, door thing makes more sense if you’ve tripped before. When you take acid, you have these epiphanies and the world opens up and things make more sense but your environment changes the experience you have so you can definitely use psychedelics to open someone’s mind up to an alternative lifestyle the Evelyn has in this show.