Not sure about the lighting. In reality, if you had a light in each room in the centre, you're right about no shadows. In games like chaos engine, they have the shadow like there is a sun from the north-west, but they were all outdoors.
I like the walls. About the door, what if you remove that black vertical line and extend what you did on the wall. In other words, imagine there was no door and you extend wall all the way across. Then for the door only edit within the V shape. I prefer the old floor.
Characters seem out of perspective. Try drawing one on sideview and you'd see my point. If the one you drew is facing 45 degrees, need to move one shoulder and leg down more to make it fit with perspective.
Looking good so far!