An excellent review of one of my favourite novels. I agree it is superb for all the reasons you state.

Firstly, Blind Pew is terrifying. One of my copies is a version with beautiful Dudley D Watkins illustrations, and the Pew stuff is nightmare inducing.

Secondly, Long John Silver's compellingly amoral character is one of literature's finest creations. You're never quite sure which way he's going to pounce. He's murderous and frightening, yet also charming, and looks out for Jim, even though you're never quite sure if he'll turn on Jim too, to save his own skin. Your observations re: the contrast with Smollett is spot-on.

You're also right about the moral ambiguities elsewhere in the story. This becomes a lot less about goodies and baddies as the narrative progresses. It's definitely a coming of age story, with Jim's character arc the vital component. It also illustrates the truth at the heart of all great treasure hunt narratives: The treasure is never the real treasure. I write a bit about that concept here, if you're interested. :)