One solution for those millions of railing posts: Instead of making posts and rails, create, say, a thin vertical box representing the railings (one on each side of a stairwell). Make this positive. Then create two thin boxes and make them parallel to the angle of the stairs. Make these intersect and group them with the vertical boxes. Now you have the railings. You can then use multi-replicate to make thin vertical boxes going across the stairs, which when made intersect will look like posts. This will reduce your object count by at least half.