However, the other issues they mention hit some well-known limitations of Rust, which don't always have a simple satisfactory solution. It's a valid criticism.

With a bit of `unsafe`, it's easy to force through self-referential structs incorrectly and violate exclusive ownership/aliasing rules (that's UB, in Rust!). Sometimes such code can be reorganized to avoid self-referential structs. With enough `unsafe` dark arts it's also possible to properly handle some self-references. However, in general it's typically a false positive in the borrow checker's model, and an annoying limitation.

For 2, I believe the pattern would be to make a generic version of the data structure as its own crate, with all the required unsafe stuff in there, properly tested and hidden behind a safe interface. Obviously that does require the data structure to be well defined and for you to know upfront what all the internal references and transformations are going to need to be (but honestly... it's probably good for that to be the case regardless).