
For far as books are concerned, Elm in Action by Richard Feldman and Programming Elm: Build Safe and Maintainable Front-End Applications by Jeremy Fairbank.
Best of luck on your journey!
Having features randomly fail on me and having to rewrite an entire library in elm vs calling out to js means less time creating features that matter to my customers! I was drawn to elm as a way of spending less time debugging my own code in production. Part of that overall strategy means pulling in tested, working code whether it's also elm or js.
Some of what I see here could easily relegate elm to being a toy language; a damn shame considering how good it is as far as strongly typed functional languages to js go.