Good photos. Unless I missed it you didn't mention the valve hole. You need to start your second row so the valve hole is "open" and you don't have spokes in the way when airing a tire. It doesn't affect the strength of the wheel, just best practice. Building wheels is not difficult if you start with the correct spoke length. Install all spokes from one hub flange to the same side of rim.Also need to be sure each spoke is tightened the same number of turns. Truing a wheel takes practice. Tighten the side you wish to move toward. Take several small adjustments instead of one or two large ones.