Sorry this is long. Glad for explanations. Gotta think on this. I would urge you to have complimentary or same or semi-modified treatment on all suitable windows if possible. This would coordinate the look from "room" to "room" and if done well, would add a classy look. You don't have to do it all at once, though. Something modest now and save up for the custom look you crave? Are the existing curtains something that you want to keep? If so, is there a way to coordinate them with additional windows? Is the fabric still available? Can you find a solid colored fabric that is a suitable match in fiber and texture that could be used to link the window areas--a band of solid or print trim on the romans, for example? I wonder what others who have greenhouse garden windows do about window coverings? It is possible to drop a roman between the bump-out window and the room. There may be moisture issues with plants, though, so you might not want the window to be too tightly isolated from the air circulation in the room: mold, rot for woodwork. I am also thinking through the window covering issue for our house and want to be ready if the "4 for 3" sale comes again soon. Have put up tension rods with semi-transparent half-curtains in new kitchen for light and privacy temporarily (see below). DH is in hunting season mode and hasn't finished exterior work, which means that the new honeycombs that just arrived won't go up for a while, and the windows in new kitchen and lobby area will not have sills and mouldings for many months yet, I fear. So I keep designing and redesigning my window treatments in my head. As of now, I plan to layer a strongly patterned roman shade over the single color honeycombs, which will allow me lots of flexibility for all seasons and will give a graphic punch to a window wall that lacks cabinets. Like you, we have purchased a door with miniblinds within the window panel. It's the front door in our new lobby and am glad we did buy it because of light issues. Am not sure how I'm going to coordinate it with the new high, wide window a few feet away, though. A quandry: Should I buy a very narrow white metal blind to match the door's blind? Even if I don't particularly want white? Belligerently, I'm tempted to use a different product altogether, to add color and texture depth and undercut the mod-ness. It's important to know as much as possible about the room before you choose your long-term window treatments. If the backsplash is to be a pattern or a real attention-grabber, you don't want windows to be competition. Same with strong colors, etc. If you're still dithering on the backsplash, try doing what I have done and get a cheap tension rod for the eating area and put up something temporarily. Sewing curtains and valences and roman shades can be very do-able. It's most work on the flat and the seams can be made straight if you use a seam guide on sewing machine. (I have a battered piece of tape that guides me.) Here is a link that might be useful: semi-transparent half-curtains on tension rods for temp privacy and sun control

You want to center around the most prominent and proximate feature, which, in this case is the window. Center the table and the light around the window. What happens on either side of the window won't matter as it is already different...in width, in door placement. Strict symmetry is only for a very formal space, which this is not; or often an aid for novices who don't yet trust their eye to create balance through massing and scale. Go to houzz.com and look at some kitchens with tables...if you look closely, you'll see a lot that is far from perfect symmetry or balance, but it all works together. For example, this kitchen...the table is not centered on the island, the island lights are not centered relative to the table, but they are over the island... and the dining light is centered over the dining table....each is appropriate to its own space.

Something like this color wise but with stripes running horizontally so it visually widens the space Jeremy Striped Handmade Flatweave Jute/Sisal Area Rug in Grey / Natural https://www.wayfair.com/rugs/pdp/andover-mills-jeremy-striped-handmade-greynatural-area-rug-w006960422.html And yes, an actual rug that is soft under foot would be preferred but has the color and texture of a jute or sisal rug. There are also some jute/sisal/wool blends that are more foot friendly. But I think a less expensive, comfortable, easily cleanable rug is preferred under foot in a kitchen. HomeGoods usually has a lot of smaller carpet options that may work.

On my kitchen window I had a roman shade that we kept up, so it only covered a bit of the glass. I removed it and was surprised how much brighter the room was. My vote is to leave it uncovered. A thin ruffle above will look disproportionately small, and anything larger will cover the glass.