Do you want to give me advice?

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Hello
I have received so much help from you before and am trying once again.
I am facing an extensive renovation but don't want to do anything wrong as the house is from 1875 and I want to preserve the charm as much as possible.

I draw my ideas in Sketchup in 3D.
A contractor will soon come here to look at the load-bearing parts.
But I want your advice so that I am not way off in my wishes and discussions.

Point 1
Our house is 1½ stories with a basement in half of the house.
The house measures 14x9m.
The green is the foundation wall, which is a stone foundation.
The other half has a crawl space that I can't access more than with a camera.
Point 2
Here, only a beam is visible, but today there is a wall; this is where I am unsure if it is load-bearing or not.
Normally it shouldn't be, but considering point 4 and that there is no central wall, I am wondering if the floor joists are laid on this wall in this part of the house, which is currently a hallway.
I want to remove this wall and put a beam there instead, as I have it according to the drawing. Could it be load-bearing?
Point 3
There is currently a crawl space here that I cannot access.
I plan to completely rip up the floors and possibly dig out to make more space, install a dehumidifier to prevent future moisture problems. I plan to build up the new floor joists with glulam beams on 60 cm centers or 30 with underfloor heating on top. (grooved board + gypsum board) parquet and tiles on top.
An alternative for the floor structure is to pour concrete to fill it all by first digging out, putting in crushed stone and insulation, pouring with reinforcement and underfloor heating. What are the pros/cons of each? I drained around the entire house a year ago.
Point 4
This is where the wall is missing, and I wonder how it was solved?
Could there be beams that reach to wall 2, or how was it done, or is there a steel beam according to the dashed red line? I can't figure this out, but it’s likely due to my lack of knowledge on this.
What do you think?
I hope I've drawn and explained it so you understand.

I would be grateful for a response.