great photos and writeup! a few alternative tools/tips:
- in place of the bungee cord, I have used a spare jackstand with a sufficiently wide top surface (or put a board/plate on top) to support a caliper so that it doesn't hang from the brake lines while changing disc rotors. Really you can put it on anything that reaches high enough so it can rest on it without stretching the line.
- if you don't have a brake piston compression tool, a basic c-clamp in combination with your old brake pad will work to compress the piston.