I wanted to prove this was entirely doable with basic hand tools.
If you've never worked with actual wood timber, I can see how this wouldn't seem like a big deal. But plywood is not even in the same realm of existence as timber. If you can, use real wood. Even a 2x4" from a big box store will do it, if you've got the tools to massage it into the shape you want.
Nope. The wires hold the PCBs in place fairly well, and in case there's a problem down the road from wear and tear, I don't want to peel off glue. But feel free to use something like hot glue, if you're having trouble getting them to stay flat.
The rotation of the LED won't have any effect on the lighting, and I wanted this project to reflect the normal build method of someone using plywood and hand tools. Crooked they are, because crooked they have a tendency to be. Could I fix it? Yes. Will I fix it? Prrrrrrrrobably not. Well, maybe. No.
A big thank you to Joey Hankins of Hankins Builders, who saved me from over-complicating the design of the box.