Keesje,
I've followed this for a while and I have a few questions :
1/- Why the leading edge flaps ? The #1 behind the props seem to be both an overkill in terms of aerodynamics, weight and dimensions ( they are also subject to the prop wash). I would have thought that the wing behind the engines will already be in a good lift-generating position.
2/-the shoulder wing choice : as a pilot, I've loathed the crosswind susceptibility of airplanes like the Nord 262 or the ATR, because of their narrow landing gear. See the balance of weight savings on a comparison between A/- structural gains in getting away from the project as it is now and B/-the advantages of a low wing, wide landing gear, wing bending moments...etc...
Another advantage of the low wing is the easier integration of the airplane with existing airport gates - that will allow you to do away with at least one integrated airstairs, hence a further weight saving.
Lastly, the fuel system would be simpler, with the added possibility of a centre tank.
Just my two euro cents.