Hello there,
These are things we have already advised a good couple of times.
1 & 2. No, 2.0 will be the last update and then the steam release, after that the project will be completed.
3. The endings were removed in 1.8 to be reworked and yes there will be more endings added.
On the suggested things:
1. Those areas won't be added on the current map, there are sections of the map that will have more content. The morning activities is a core element of the game, adding them as regular places is unnecessary.
2. You can find characters around the map doing their own thing, like Ken at the library or Haniya and Gabriel at the park. At most one more character will join the studio, and the church already has multiple encounters, adding more would just make it convoluted/ not everyone goes to church.
3. The pool has multiple scenes, not just Norah's. Asking for a milkshake has a scene tied to it. Adding characters for the sake of adding them is not something that will be done, as an example, both the characters you mentioned have 0 reason to visit the public pool.
While there are parts of the game that are for immersion, like taking a shower and brushing teeth, some will get improved. When you help Anna clean or dishwash, not having a scene doesn't make it "not useful/ have nothing", you are raising your relationship with her, there are also places where it might appear as there is nothing, but there're characters named/unnamed that can show up for some dialog, not having a scene doesn't make it not useful, is world building, it shows characters do other things outside of just interacting with mc.
4. Characters do interact with each other in some parts of the map if is somewhere they visit, there could be more in the future, but not all content is just sex scenes, and not all characters have a reason or would interact with each other.
5. All of the places you mentioned have repeatable scenes. The Kate and Himari example already happens and they even have scenes.
6. The mentioned places already have minigames/random events and scenes.
On the last statement, all good things come to an end, there are multiple routes and decisions matter. This is a side project and will be finishing with the steam release after 2.0. A break period will happen, and the next side project will take its place.