It is difficult to see with the pictures, but Is there room for the TV on the wall opposite the fireplace? What kind of help did you need with the mantle?

Reduce to one or two things on mantel -- it's too high for a lineup of knick knacks. I'd either lower the TV and put a grounding piece of furniture, or try to move it onto the wall by the gray chair and see if you can rearrange to use that location. Hard to stitch this together into good estimates of distances...

Lower the tv. Put the recliner and gray chair where the sofa is. Float the sofa parallel to the fireplace wall, more or less even with the half of the patio door that doesn't open. Add table or floor lamps where you need them.

Remove all the knickknacks, then choose three to put back for winter season, a different three in spring, and so on. You can get 11 by 14 inch enlargements of the personal photos to frame for the walls.

What materials are the fireplace wall and the hearth. I can't see the hearth very well, but it doesn't look like it goes with the wall.