I would find out what your local building code is for stairways, step width, stair tread, riser height and incline,, just as you think.. this is complicated. just because it's grandfathered in doesn't make it less of a obstacle just makes it a legal obstacle that someone can always find a lawyer to help in filing a suit.. 

When we purchased the house, it was just used as a decorative wall that stood out from the living room/stairway area.The person we purchased this property from glued weird "tiles" on the chimney for decoration.

They'll make sure all the windows work, and that the smoke alarms are installed correctly, that any stairway with more than 2 steps has a railing, etc. 

I assumed that the stairways being too steep were the only (fixable) impediment here.

I need to figure out where my training begins on here, It can be a stairway to disaster to invest out of state as a new investor if you're not very familiar with real estate.

although I might have used "Stairway to Heaven" for that sad little set of porch steps in the back yard...

One looks like it has a stairway in it.

Hallways and the stairway down to the bottom floor waste a LOT of space in most houses that aren't huge. 

Taking this to the max would involve no stairways (because they waste space) and every room having a private entrance on each level with one kitchen and bathroom per level.

Hallways and stairways waste space so really try to minimize them.