Good question. We decided to go with a mini split or multi split heat pump rather than run all the duct work along the ceiling.

Thanks for your comments and I'm sorry for the confusion in my original posting. I should have made clear that the 2nd picture above shows our staircase in the process of being remodeled. It is not the finished remodel. I'll upload some demo and "before" pictures below. I hope they'll help with some of the questions. Here is more background on this project. If anyone reads through this or looks at the photos below and still has structural concerns I would love to hear it along with any reasons for that. This is the last piece of a total townhouse remodel. The staircase has been difficult because of conflicting advice from subcontractors. As you can see in the photos below, the half walls were torn out and replaced with framing for the installation of spindles and handrails. The architect's plan is to replace the carpeting on the original steps and put false treads and risers on the new framing. Those are the black things you see in the pictures (the risers will actually be white but these are just mockups). Our carpenter did have structural concerns with the architect's plan and he backed out of finishing the project for that reason. We brought in a structural engineer. The SE said the new framing was solidly attached to the original treads. He didn't think we needed to put full-width treads under the carpeting for structural reasons. At the time I wasn't thinking about how the steps would look style wise. I was preoccupied with getting the spindles, newels and handrails I wanted. My husband wanted carpeting and I conceded. In hindsight I guess the new carpeting was put down prematurely. We're now finishing the project with a woodworker. Since we have the ok of a structural engineer and the architect confirmed the plan is to code I was hoping the issues about trim and the drywall were the last things to resolve. Thanks for your advice so far on these issues. Unfortunately we cannot start the staircase all over for style purposes only. We would start over for structural reasons if needed. Thanks in advance for wading through all this background.

I like the first option of putting your tv on the 21.9 wall with built ins. If you did this I wouldn’t push your sectional all the way back to the back wall, I agree that is too far back. What if you moved it up and added a table behind the sectional? I’ve seen a few examples recently where a bar height table was added with bar chairs for additional seating (sample in below link, sorry I don’t know how to add it as a photo). https://www.houzz.com/hznb/photos/family-room-home-theater-and-bar-contemporary-family-room-san-francisco-phvw-vp~2787162 I also wonder if a sectional is the best bet for the size of the space, what about a large sofa with a chaise on one side? It could keep everything facing the tv. Just a few ideas, it’s hard to picture the room with just the floor plan, especially with the stairs coming down the middle so I could be wrong. Good luck!

It looks like you don’t need it to be an en-suite, is that right? Then your idea to seal up that door and move the vanity over makes sense. And you’d like a 5’ long shower? That’s a nice size, and room for ledges or a shallow bench to hold shampoo and soap. Is there anything preventing taking out the dropped ceiling in the shower? Where are the controls and the shower head right now? If the controls can be on the wall under the vent, and the showerhead at the back (on the short wall), that would be nice.