Hi. We are considering the same thing (will attach the link pic we found on Houzz that we like) as we decided we would rather have one big open uninterrupted island rather than plonking a sink right in the centre. Inevitably stuff gets left draining/sitting/hanging around the sink so would rather not have it on display. And also every time you have visitors you end up standing in the kitchen around the island so better to have one large space. We were a bit concerned about the cupboards above but found plenty of photos of others who had done it and thought why not try. https://www.houzz.co.nz/photos/kitchen-phvw-vp~271728

The only problem I see with placing plants anywhere near the steps, if leaves fall and are not cleared away, they will rot and become an eyesore as well as slippery if stepped on. Also it may reduce the space as the plant/s grow, as you use the steps. I think placing screens against the grey wall in a fancy pattern would look nice and is basically maintenance free. I would also paint the steps, maybe in the same shade as the screens, though I would leave the railing as it is closer to the window and you don't want to make it the feature.

You could add a chaise lounge or a comfy chair and table for a reading nook or an office area if you need one, a computer area but whatever you do don't over clutter it keep it sleek and sexy and or a comfy chair as suggested with a little side table for reading, I also like the idea of a place to put coats, shoes etc if you must enclose it. Maybe even a small wine bar? with a couple of stools. I decided to google is and will give you a link to many pics to give you more choices. https://www.google.com.au/search?q=pics+of+what+to+do+with+space+behind+floating+stairs&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjFy-n9p4vZAhUEF5QKHSvhAOMQ7AkISg&biw=1280&bih=893

Hi Louise - thank you for getting back - a little hard to explain but ill try my best - by the arm I mean like an extended pole that would go from the wall light (that would sit on the wall - would be longer - sort of like a stem coming down from the light what ive seen so far is mainly decorative im thinking) but maybe where a cord could be hidden therefore no hard wiring required - basically I don't want the cord to the plug in to be seen as the wall is bare). Have I confused you completely? Cheers wendy