What motivated me to have the basement access in the dining area? That you don’t have this access in the living area. Even if you have a home office downstairs and come up to get a coffee, the route through the dining room/kitchen is much more practical. Whether it can be a sliding door still needs to be clarified, as well as the door from the hallway/kitchen. It has to run within the wall.
Of course, the right side wall of the guest bathroom with the open hallway situation can certainly be moved 10 to 20 cm further to the right.
I would keep the storage room upstairs. It fits a central vacuum cleaner, mop, etc. wonderfully. A cabinet for toilet paper, towels, and bedding, which should be accessible to everyone. I would even have a water connection installed there to keep the option open to possibly place a washing machine/dryer upstairs someday. Because if you don’t feel like carrying the laundry back up after washing. Or just to have water for mopping, etc.