The first photo is of the pavers we love, next to the already established honed concrete. Second photo of the house, the area we need to complete is currently covered in carpet. The third photo is of the paving sample sitting on top of an exposed aggregate concrete sample. We probably like this one the most out of all the exposed aggregate samples we looked at, but we are not totally into it. On the right side of the picture is the established honed concrete.

Maybe a gloss light grey subway tile? Glass mosaics can look stunning but there are a lot of grout lines to keep clean, particularly behind the stove.

strip part of the brick and mantle back to orignial if the exposed colour lines up with the room, strip the whole thing. Looks so well crafted not to pay respect to the past

I wonder how much time you might have to spend cleaning the roof behind the parapet, perhaps the rain will take care of that, leaves?. If you were going to use these spaces as terrace you would need to adjust the height of the parapet or add a railing, if not the height of the parapet could be reduced