I finished the game (v2), your walk-through certainly did help! I found that the weak spot was the one with the ceiling, it felt strange to have to use something referenced only in picture, but in no way mentioned in the text, I doubt I'd think of that on my own :)
I found a bad bug: if you reset the correct switches, but keep on resetting them, the game gets in a bad state, where the lights are off forever and they will never turn on back on again, you have to restart, as the good combination doesn't work anymore :(