Privacy could be obtained with a screen, placement of potted plants, an open bookcase, but I like your idea for a curved track with a curtain as one option for visual privacy. I would rotate the dining table 90 degrees and move it towards the balcony. I would remove those two chairs/tables because the layout of a single chair that far apart from another chair does not work. You may need to move the seating away from the main entrance because it looks like you walk in and you're on top of a loveseat. In such a tight space with so many doors that open in to the main living/dining - my advice is to keep it simple. Scale the furniture properly and have pieces that are multi-functional. Example- an ottoman that can serve as seating. A bench at the dining table to seat 3 on each side. I would also place two smaller loveseats facing each other in front of the fireplace. This will give you an "entry area" (along the back side of the kitchen wall) and help to define the living from dining rooms. Even if you don't have a formal entry, try to create a bit of space to welcome people.

Need more information...........what is the height variation or fall from the elevation at the top of the stair and where the run would end at the lower landing? What is the length of the run in a horizontal measurement? These are all factors in the code compliant design of the stairs.......not just the width.

we do in guest bedroom,, but not sure will go with colors I have picked out, and the great room is a vaulted ceiling ....I guess we will just have to see...our house is being built and will be very open..not alot of wall space.

Scope of work would benefit from consulting a security company.