How do I best handle uneven interior walls in the kitchen, frame out?

[Sussien]

Hello,
My first post here on the forum! I've been checking out a lot here and have been helped a lot, so thanks for a great forum!
I've bought my first house, from the 1930s, a bit crooked when you start looking closely.
I'm going to install an Ikea kitchen and run new electrical wiring in the kitchen. The electrician suggested minimally framing the wall to be able to run the wiring nicely but also because the walls will most likely need to be adjusted for the frames to be installed.
How would you have done in my case? Frame out the walls? If so, what is the minimum measurement? I don't want to take too much of the room's space, so to speak.
Then the floor is a bit uneven in front of the chimney, with a plastic mat on top, unclear what's causing this but maybe there's tile or something underneath just there. It's a small elevation but noticeable when you walk there. I had planned to lay click flooring throughout the kitchen but I'm wondering what is best to make it even and to prevent the new floor from coming apart due to the difference.
A lot here in one question but hoping for some good thoughts from members with similar experiences
The house has a timber frame.

 

[BirgitS]

Then the floor is a bit uneven in front of the chimney breast, there's a plastic mat on top, unclear what causes this but maybe there's tile or something underneath just there. It's a slight elevation but you can still feel it when you walk there. I was thinking of laying click flooring throughout the kitchen but wonder what to do to make it level and ensure the new floor doesn’t separate due to the difference.

There might have been a wood stove there once upon a time, and it stood on something spark-resistant, like bricks or a concrete slab.

You could either embrace the house's history and let the bricks/concrete slab be visible as decoration while laying click flooring on the rest. Many are starting to use the original subfloor as the kitchen floor, sanding and treating the pine or spruce boards. But you can also lay construction boards over the entire floor before placing a new click floor on top.

 

[Sussien]

There may have been a wood stove there once, and it would have been placed on something that can withstand sparks, such as bricks or a concrete slab.

You can either preserve the house's history and leave the bricks/concrete slab visible as a decoration while you lay click flooring on the rest. Many people are starting to use the original subfloor as kitchen flooring, sanding and treating the pine or spruce boards. But you can also lay construction boards over the entire floor before laying new click flooring on top.

Thank you so much, Birgit! Yes, your suggestions about what's underneath sound likely. I simply have to open up and take a look. I'm worried there might be asbestos under there, so I preferred not to open it, but it will be difficult to sort this out without Or as you say, lay boards of some kind and maybe extra foam under the part that isn't raised (which is most of it). Have a nice evening!

 

[BirgitS]

Thanks, same to you!

Not several layers of foam as it becomes a bit spongy, but you can use 3 mm thick masonite (board) and/or a few layers of lumppapp, 1 mm thick, where there are depressions.