There’s a good list of resources on the PunyInform GitHub page. From memory, @fredrik’s tutorials are quite good for beginners.
@otistdog has prepared an excellent list of documentation. Most of this is relevant to PunyInform, albeit with some modifications.
That’s true. The techniques you were asking about are in one or more of my games. You can download them or play them online at my itch.io site. You can find the source code, maps and solutions at my GitHub repository.