I think it has the potential to look fabulous or look really tacky. It would depend on the house you use it in. I think having the height helps create that light airy feel... I have seen it used to enclose an external staircase and it looked wonderful, it created a feature of this lovely lightbox on the back of the house. I think used as a feature in a modern build it can really look good.

I like it as is. I'd maybe consider a feature pendant light (or three) in the "void" above the stairs going down, but with the unique ceiling I don't think it needs it. Maybe a piece of art on the upstairs wall that is directly opposite the entry door. Something abstract / simple so that it looks nice when viewed from a distance (i.e. the front door). Otherwise, is there anything you *need* in the entry? For example, a bench or stool to put on and remove shoes? A small table to place mail, keys, sunglasses, etc. Some hooks for umbrellas, coats, hats, etc? A mirror to double-check your appearance before you leave the house?

Love to see personal styling rather than matchy matchy show home look! I love the cane chairs but you don't want it to look crowded. Though you could put one to the left of the room facing the other way so it's more conversational rather than everyone facing the TV and with their backs to rest of the house. I love that Freedom lounge it'll look great. I'd probably add a rug in a warmer texture even a plain or patterned sisal to soften the dark shiny floor (the dark colour makes your room look smaller and is a bit stark against your nice warm timber) and anchor the furniture together, Freedom and West Elm also have great options.

I would paint the wall with Bulls Eye 1-2-3 Primer made by Zinsser which can be painted over any type of paint without sanding, just a wash down. See before and after photos of what I did over 10 years ago when faced with timber panelling in a few rooms.