Finished demo.
1) Panels are one of the most useful tools. They allow to store a huge amount of logs and let them burn all in one go. Just select the panel holding the logs. It automatically moves it and let the logs pass.
2) Slides are horrible to use. Because the game physics counts pixels, if they are not properly aligned, the logs will stop sliding when they intersect.
3) Fans can be used to move logs instead of using the mouse grab. Mouse grab is terrible, because the logs keep moving freely. Prefer to use the fan to sweep the logs.
4) Trampolines are glitchy. Their hitbox allows logs to pass through when there are multiple logs colliding at the same time. Also, they become unselectable when covered by logs.
5) Even though each level requires some brain, the easiest way to beat any of them is to let it run for some time, buy a large amount of tools and them finish all quests/objectives.