First rule...as was already mentioned, you can't have any junction boxes buried in a wall or behind a bookcase without providing access to that box. They all need to be accessible. I've done what you're describing many times. There are a couple of options to think about if I'm reading your situation correctly: If you can bring the existing outlets forward and incorporate them into the back of the bookcase, on the bottom shelf, that's great. The easiest way to do that is to match the location of the junction box with a hole on the back of the bookcase. Then remove the screws that hold the outlet to the existing box and pull the outlet through the hole in the back of the bookcase so the outlet is now in the bottom shelf area. Then use a box extender to increase the depth of the existing box to bring it flush with the back wall of the bookcase and then remount the outlet to the box extender. If you need to add more outlets in the bookcase, you can extend the circuit off any one of the existing boxes as long as you don't exceed the fill capacity of that box. That normally won't be a problem, as the box extender will increases the volume of the box. You can make that extended run out of romex (or conductors in conduit) and run it, properly secured, either through the toe kick of the bookcase, or even up and along the top of the bookcase. You can even run it down through the floor, into your basement, then back up through the floor to where you need it to be. You can make fishing space between the back of the bookcase and the existing wall by screwing furring strips through your drywall and into the wall studs. Then screw your bookcases to the furring strips.

Ana Marie, My husband and I installed IKEA closets in our previous house. We only lived there around 4 years after that, but they still looked new when we left and I actually liked them better than the custom made ones I have now. The kitchen in that house was also IKEA, installed before we bought it, and they were also holding up just fine after 8 years. I had knicked a couple edges near the microwave insert, but I'm sure I would do that to any cabinets haha.

Wow, thank you all for the great suggestions! Replacing furniture is not an option - if we end up moving it will be a downsize, so not looking for new furniture Definitely like the idea of a new rug. Is it necessary that the chairs are entirely on the rug? That would require an 8x10. Won't be too big for the space? Already planned on replacing the fireplace doors with black. The brass is also from 80s Fan is also an 80s throwback. It does help with airflow in the room, but is not attractive. Shelves are adjustable expect for the top triangle. There are can lights on either side of the fireplace which are not visible in the orig photo. I typically use these only at night because I don't like ceiling fan lights. Here are more photos of the area. The kitchen and breakfast room are to the left and used to have the same oak cabinets, trim and crown. Breakfast room also had stained windows, trim, and chair rail (i.e. all 3 rooms were stained to match). A few years ago we remodeled this in white but did not touch the adjoining family room. My initial thought was to make the bookcases match the kitchen cabinets. But maybe just changing décor as suggested will suffice.

I love your character filled space. I remember this and the work that you did with the kitchen area. Because it is a smaller space I don't think I would add another bookcase. As long as it looks balanced I think it will work with a table as you had planned. You may need to add some artwork to balance it out and maybe move some other art you have around on the other walls so theres not too much everywhere. I love the colors you have as well and the mobiles are a fun touch.