Building Architecture / feasibility check

Hi there,
we're about to build a House in southern Germany and need some Help of an professional to check our floor plans in relation to:
- structural engineering
- dimensions
- feasibility

>>>>To the key facts:<<<<
- House will be a semi-detached house
- buildingsite (see attached):
property 6751: 374m²
property 6752: 469m²
- per half about 8mtr x 12mtr ; +/- 1mtr no problem.
- terrain is slightly increasing (heights.pdf)

>>>>What is special and has to be payed attention.<<<<
<OUTSIDE:>
Front: The two houses should NOT be mirrored! They have to be look like a huge Villa, not a semi-detached house.
Front & Side: you can play with offsets and different window sizes to make it look more like a villa.
Side: a huge widow element that goes through two floors

<INSIDE:>
- lot of "airspace as you can see in our floor plan:
Basement to ground floor at the stairs
ground floor to first floor at the dining tabel
first floor to top floor a small gap at the stairs
- Shower in the nature: how can the shower placed with outside vertical gardening as a natural privacy screen?
- cozy place in the first floor: desk at the big airspace with the look at the huge windows that goes through the two floors.
- Hidden utility room beside the kitchen.
- top floor in the first unimportant... maybe sauna, Billard table or bar...

>>>>Where do we help in the Design<<<<
1.) Look at the ground floor plan: Which direction of the stairs is right (basement to ground floor)?
2.) Where do we place the guest toilet and wardrobe? Beside the stairs or behind the stairs?

So, i think our plans are not that bad, but we need some input of an professional...
Feel free to ask questions if you need further informations!!