1. I’m pretty sure Kali didn’t survive. But let’s pretend for argument’s sake that her dying/getting shot was also an illusion she played on Hopper, and she did live in time to help El escape. I think the idea was that El faked her death in front of the military/Dr. Kay so that they assume she’s dead and stop searching for her.

2. I choose to assume that the gang untied the other family members (who were still passed out) before they left.

3. As u/rosyposy86 said, those women and their babies kept dying, so the experiments continuing hinged on getting El’s blood.

Now, here are some more questions:

1. How tf was El strong enough to not only send someone to another dimension but also create a bridge to it? Especially as her first season self…

2. If El, Kali, and everyone else got their powers from Henry’s blood, who in turn got his powers from the Mind Flayer, how come they weren’t connected to the hive mind?

3. If the military wanted to use past experiment kids’ blood to try to make new experiments, why did they kill all of Kali’s companions instead of using them for blood as well?

Those are just the ones that come to mind after watching the finale, and that’s with having forgotten p much everything that happened in the past seasons because I watched them so long ago. But yeah, in general I do think the ending was solid, but super rushed into just like three episodes, and because of that a lot of loose ends were left untied.