As for the brake wiring, that's a rather difficult problem to solve. In my pedals I use a short length of stereo cable (three conductors, exactly what I need for the sensors) that I have run through the sleeve part of some old shoe strings, and I left them in a wide unsupported loop over each joint. This gives an acceptable look, but it will eventually break. it might be opssible to use a stereo jack for each joint, but the sliding contacts will introduce noise, that might cause more problems than it solves. I think the best option would be to cut a few lengths of coiled stereo cabling (https://www.google.com/search?q=coiled+stereo+cable&tbm=isch), 5 cm or so for each joint they have to hop over, held in place with zip ties. It seems to work well enough for steering wheel stereo controls on cars.