What is the geographic location of the planting site? If you have the right climate for star jasmine these would cover the entire wall in time, if your panels were big enough. With their existing size the panels are eventually going to be too small for these plants.

With its arching habit butterfly bush will not really fit well in your narrow bed and it needs full sun.

As does turf-grass. Also this is kind of a small space to have a lawn in, you should probably surface it with concrete pavers or stone pavers instead. Then you will be able to walk on the entire lower area without stepping on soil or in damp grass - covered with pavers the area would serve instead as a patio, as an extension of the deck.

Lavender must also have plenty of sun. Depending on what, exactly you mean by a "chorus line" of additional plants with your evenly spaced panels and evenly spaced star jasmine plants, the rectilinear geometry of the architecture of the setting you are pretty much stuck with continued uniform and formal planting. Otherwise the whole will not be cohesive, with random looking planting not matching the existing elements.

Geographic location? This pertains directly to plant variety selection.

Softening the lines by not shearing otherwise geometrically arranged shrubs would be one thing, scattering plants around in an informal manner would be another - I still can't tell what particular approach you are referring to here.