I don't have the window, but this is what mine looks like. Instead of an island, which would be hard to navigate around if there is more than one person, I used a mobile cart. It's worked out well so far.

The staged room is lovely and I think you should follow along. A 3-seat sofa and two armchairs work in almost any setting. Of course, the sofa should be 18" or less from the coffee table, so if you want to center the table with the firebox opening, the sofa will have to scoot closer. I think the TV built-in is well located, but you could change the color. I'd have a pro paint it once you've determined the colorway. In both arrangements the art is a bit too wide for the FP. Prefer to see it no wider than the firebox opening and hung 5" above the mantel without rising above the window frames. What's your plan for drapes? I think they will make the space if carefully chosen and hung. Is that hardwood or carpet? Difficult to tell from the pix. On the entry side of the room you could add a console table, lamp and art. I think you need more task and accent lighting. The ambient lighting coming from the ceiling seems fine, but lacks the intimacy that table, floor and art lamps add.

I would have left the entire deck light and natural, let it complement the mortar and fit with the natural outdoor environment, but since you have already stained the top rail you may be stuck with staining the entire deck. I would start with stripping the stain from the top rail and see how it impacted the color. Then I would re-stain with something that has a more natural feel, (Walnut, Chestnut)

I think your headboard is quite lovely so I would keep the drapes simple. I like the color of the panels you have now but they need to go wall to wall. You need to install a proper rod though! One that doesn’t sway in the middle and preferably won’t show! Since you won’t be utilizing the window install a blackout shade so the light doesn’t filter through it and distract from the look of the luxury of full wall of drapes!