I wish I could give you general recommendations but as anyone who has read my posts over the past 7 or so years knows, I design custom homes and renovations using a process that does not begin with finding a plan. I only see pre-designed houses when they are posted here. For example: One of my clients hated stairs and by the end of the design process the entire house was square with a series of quadrants spiraling up around a central stair. It had turned out that it was floor levels that did not communicate with each other that she hated. The top level overlooked the living room and the view of the Green Mountains was spectacular. It was actually pretty inexpensive too. Another client had an extensive art collection so I put a wide formal hall along one side of all of the living spaces. I recently visited it and the second owner had a far better collection; It was like a grand gallery in a museum. A client on the Cape had bought a 60's Yankee Barn with a heavy timber exposed structure and a 2 story living room. In the winter they were so miserable in it that they hired a local architect to build an addition next to it so they could use that in the winter and the Barn in the summer. No matter what they did they couldn't get satisfactory lighting in the living room. I took over the job and finally convinced them to say goodbye to the Yankee Barn and put a second floor in the 2 story space. They saved a small fortune and we saved a few beams in a bedroom as evidence of it's history. IMO the design of a house is a collaboration between a family and a designer. I believe I am able to create good solutions for people because I listen to them very carefully and I am not afraid to suggest unusual solutions. Of course, I always let them feel that they were part of that discovery because, in fact, they were. So all I can recommend is to start at the beginning of a structured process and allow everyone to be part of the process by carefully moderating the discussion. CAD floor plans can be so restricting and distracting during this process that I try to only show clients a hand drawn sketches until it is time for final design approval. A CAD drawing acts like Vonnegut's Ice Nine. Here is the dreadful Yankee Barn:

Post in the kitchen forum. There are quite a few layout experts there to help.

I'd center a sofa table under the window, with either some plants or lamps on it, and then push the sofa up against it. With all of those built-ins, you've got ideal toy storage, game storage, blanket storage, more than enough storage, and even better, it is behind doors. Once the couch is pushed back, you can experiment with the chairs, either flanking the fireplace, or flanking the couch. It's hard to tell what exactly will work best from the photos. Are those vertical blinds on the large window? We have a window very similar to that. Our home came with vertical blinds on the picture window that drove me bananas! We replaced the blinds with a single solar shade that rolls up and down with a chain; so much better! Our couch sits up against the window and we can now close the shades without climbing on the couch. (Pictures here.) You could do stationary curtain panels on each side of the windows. I like your paint and trim colors. It looks like you might be gravitating more toward lighter, brighter colors, so you could paint the built-ins white and lighten the space (the wood will be more forgiving of little ones, though...)

Scaled floor plan with everything in it would be themost help.