Rails needs more opinionated decision on frontend story. Just pick ReactJS instead ? Not a bad idea. Or VueJS ? Neither a bad choice. It's the main reason i don't choose Rails over a universal Node.js stack for the HTML rendering part.
First, CoffeeScript is formally deprecated. Turbolinks sucked, but Turbolinks 5 is an entirely new beast and it rocks. You need to give it a second look. I recommend this talk, sped up to 1.5x:
Thanks, it's an almost complete guide. But there's one important missing piece: Universal routing. How about taking the routing config which can be applied for both server and client ?