Since you use them- They are functional wall art.... Frame them with picture moldings on the wall. Double moldings:

This full wall treatment is awaiting its big TV.... Add your guitars to the space on either side?

Or use board and batten (adjusted to the size you need)

open franes with backing

Rustic look

To begin with, your windows badly need drapes. With the curtain rods installed past the window so that the open curtains can be stacked beyond the window pane, that will take away quite a bit of wall space.

I'm somewhat puzzled since you mention dining/pool table but I'm also seen living room furniture there (by the way, your lamp is much too small and short). How will that work? If it's a combination of the two, you really need more than a couch to make this a living space.

Good idea on the drapes although that seems to be the style for the more modern homes out here; I'll contact the local company we worked with (for our shades) to see what the options are.

We have a huge back room (adjacent to the front room in the photo) that serves as a primary dining area and TV/family room along with our kitchen.

The combo high-end dining table/bumper pool/poker table (in this front room) is for when we have parties - so we can have something that has multiple purposes but, if necessary, can seat additional people for a large gathering.

There is a leather chair in the corner that is barely seen (in the upper left) of the photo. We'd probably get another leather chair (of the same color and wood).

More guitars. You cannot have too many.