In older homes, it was COMMON to have hardwood used for the flooring only on the main floor where the family room, kitchen and dining rooms were. On the second and third stories, where there were only bedrooms and bathrooms, you often saw softwoods (like fir and pine) being used for the flooring. I'm guessing redwood is as hard as fir or pine, so you could probably use it in your bedroom provided you remembered to lift furniture to move it instead of sliding it across the floor.
I've been in a lake cabin where all the interior walls were stained and varnished wood rather than plaster or drywall. You could use that redwood on interior walls in an office or den. Have tongues and grooves milled into the boards and set them at a 45 degree angle on the wall (or not).