The Aleppo pine, as a species is a problem child for bonsai. It reverts easily to juvenile foliage. You will frequently end up with a blend of mature foliage with medium green needles in bundles of 2 or 3, and blue-ish juvenile needles, that appear as single needles, looking more spruce like, This mix of foliage types drives people crazy. An older well ramified tree will have mostly mature needles, but trimming can trigger a new flush of juvenile foliage. Not impossible to deal with, but a distinct difficulty.
Your tree has a curvy trunk. Curvy trunks should not come out of the ground bolt upright. At the next opportunity to repot, you should change the angle the trunk leaves the soil. I personally from the photos would tilt the trunk to the right, tilt enough so that the first branch on the left comes off the trunk as horizontal, rather than drooping.
Through the rest of the tree, remember, branches should come off the trunk at the outside of a curve, not the inside of a curve. Remove all the "inside of a curve" branches. Try to keep the outside of a curve branches, but where you have several options, the one on the apex of the curve is the one to keep.
Not all of this needs to be done at once. Myself I would likely transplant and change planting angle in your normal best season for repotting. Then give the tree a year to grow without pruning, maybe wire a few of the lowest branches. Following the year after repotting I would begin pruning. But I live in a relatively short summer climate, depending on how your tree responds you might be able to do more work in a single year.