I love the little dog at the top of the stairs. SUPER CUTE!!!! I do love your staircase. Lovely.. But I so get wanting an update and going with a different color. I agree with Tqtqtbw... I think going lighter would be really pretty. Maybe a fun change. I don't think you should paint over the wallpaper. That will only come to haunt you in the future. If you can afford a painter see what they would charge to remove the wallpaper and repaint. If you are doing this yourself you might discover with a little music or a book on tape the work goes by fast. What other colors do you have in your home? Do you have more of that pretty plum? Maybe you need something to go with that? I do like your rugs!

I'm no expert, but I don't think you should do shiplap or paneling, even though I have a house full of dark paneling from the 60s that I painted white in the 90s and I am reasonable happy with the look. I would remove the framed mirror from the dining wall and leave that wall blank. I would also remove the white relief artwork from the hallway--I don't think that every wall needs to be decorated. Remove the "C" above the sink and the tchotchkes over the kitchen cabinets and elsewhere else in the room. I would also look at inspiration photos to figure out something simpler and bolder for the mantel decor, because I would think that's where you want the focal point of your kitchen and dining area to be.

I rolled my eyes at, "bldr thought that’s what I wanted as wainscoting"--builders making assumptions rather than asking is a bit of a pet peeve. I like the board-and-batten panelling (last inspiration pic from the OP from 3 days ago), but I think beadboard would be fine. I have V-groove panel in my house, which I prefer to beadboard but you have to REALLY want it, as it is less available and more expensive than beadboard for what is really a pretty similar look. Repeating the shiplap would harmonize with the hallway, but if shiplap wasn't what you wanted originally it seems like a mistake to double-down on it.

@Sabrina Alfin, our farmhouse is not very rustic. The beadboard is a little too busy for my style. This is our exterior: @WestCoast Hopeful, a gallery wall was originally my thought, too. I ended up doing a 3 x 3 gallery grid wall on the landing of our U-shaped basement steps from our 3 week Alaska/Canadian Rockies trip from a few years ago. I painted the accent wall Behr City Rain which provided a nice contrast to the SW Repose Gray. Since I'm leaning towards putting in a narrow console I'm not sure that a gallery wall would work with that as a focal point. I'm still mulling it all over, though. We went with one main color in our house (SW Repose Gray) and used BM Half Moon Crest in the master and the laundry room. Even our cabinets are SW Repose Gray so I'm wanting to add a little more color to certain spaces. I wish I could pin down my style as I like certain aspects of modern, MCM, transitional, Scandinavian, Boho, farmhouse, etc......lol. Since I need to repaint the hallway anyway where the drywall was repaired, I thought I would test the waters in this space with adding more color.