Hi,
you have a beautiful apartment. You and your familly will enyoj living here, so I decide to create a warm, bright but colorfull home.
Like you want, I keep the original doors, kitchen is now in the room B with dining and living room. All in colors. Kids room is with big walk-in closet with sliding doors, so you feel like the wall is in line. Also, the desks are not necessary now, you can buy it later, so the kids will have more space for playing. In landry I will keep the tiles and put a big sliding doors. Behind you can have a wash mashine, dry mashine, shelves for clothes in half space, and second half side can be small office. On the other side, you can ironing and keeping some things for sewing. One bathroom is master and you can use it from master bedroom. The hall I make like you asking for: build a loft like a two wardrobe for storing, so you can catch the things from hall, and I keep the store you alredy have.
I hope you like it.