[kach22i]

Learning some of the terms would not be a bad idea as someone mentioned (Z-Girt etc....). Look at some wall sections and other typical drawings.

The large span ones using arches often use cables under the slab to contain outward thrust just like wood arches in churches.

The metal is just thick enough to do the job, one dent on a column (just folded metal really, not a true "H" section) and it is toast.

Architects are still used to assure meeting local building codes, structural engineers for footings and concrete slabs, civil engineers for the site plan and so forth just like a real building. There is no law which says these must be ugly eye sore buildings, several firms I worked with made them look pretty good with a few tasteful decisions.

Good luck.