If you want useful -- I highly recommend a small table with two chairs in the one end. Also, bookcases with glass fronts, or, like I did -- one bookcase and one secretary that closes up to hide the paper and computer monitor. I use my 36" square table for so many purposes -- morning coffee, afternoon tea with a friend, making jewelry, drawing, computer, solving jigsaws. Mine has two leaves that pull out, so I can also bring chairs in from the dining room if I want to have four people in the space. My space isn't crowded. There's at least 4' of space between my table and the rug. You're fortunate to have fewer doors and windows, and a 15' width. My 1939 living room is 12' x 21', so it's divided into three spaces instead of two. My secretary and bookcase had to be on the other end of the room.

I think you really need to look at the costs associated with moving walls and the kitchen and bath to get an office and curved stairs. The easiest and cheapest solution is to put your office in either bedroom and leave the floor plan the same. Take the money and time you save to update the kitchen and bath fixtures if needed but You still have not shown us what you are starting with except the stairs. Please post pictures of your current space! I think this is a waste of time and money unless you've found that money tree I've heard of. Good luck though. We really DO need more info from you to give you better solutions.

Well to balance things out I would start maybe a larger desk facing out into the room rather than facing a wall. because the room is small it might look good angled in the corner. I think the number one issue is the room is a bit small and the giant printer has taken over .. not much you can do about that. Try that desk on an angle facing the printer. Than I would get a true desk light. What is the main thing you do with this room, I mean time wise, I dont see a computer or files, so I'm wondering if its more of a good location for the printer .. rather than an office?

A fireplace in the corner limits furniture placement. A sectional sofa limits furniture placement, but if you're wanting a single sofa large enough for a large family, that might well be your only option. The other drawback of a sectional sofa is that if any part of it gets worn or torn or stained, then you could end up needing to replace the entire sofa to be rid of the problem. How many people -- adults/children -- do you need to have seated and what are the ages of any children? How do you feel about a standard two seat sofa for adults and modern bean bag chairs, easily movable to/from bedrooms, for the children? https://www.google.com/search?q=modern+bean+bag+chairs&client=firefox-b-1-d&source=lnms&tbm=isch&sa=X&ved=2ahUKEwis1cXLovnvAhWZElkFHROSBZoQ_AUoAnoECAEQBA&biw=1329&bih=620 The room is not huge and you don't want to crowd it -- especially if you're adding a bar to the island -- so you might want to use narrow tables. https://www.wayfair.com/17-Stories--Mayon-End-Table-X113953506-L442-K~W002842495.html?refid=GX433553610453-W002842495&device=c&ptid=902723281400&network=g&targetid=aud-354999624671:pla-902723281400&channel=GooglePLA&ireid=107198117&fdid=1817&gclid=EAIaIQobChMI3uzi1aH57wIVwZJbCh0hBwaTEAQYBSABEgJiR_D_BwE or even portable tv tables rather than larger, more traditional end/side tables. https://www.wayfair.com/Zipcode-Design%E2%84%A2--Siloam-C-End-Table-X112527357-L442-K~W000914252.html?refid=GX433553610453-W000914252_1874718480&device=c&ptid=966746374237&network=g&targetid=aud-354999624671:pla-966746374237&channel=GooglePLA&ireid=98554965&fdid=1817&PiID%5B%5D=1874718480&gclid=EAIaIQobChMIpJy3kqL57wIVZYlbCh3ynA1XEAQYBCABEgKJsPD_BwE