Guide Early Game Tips From A Level 40 Random Who Has No Idea What Happens At Level 50+

Yes.
Playing Shaman, most end-game builds I found were 1.19 so many included Ornate Shadow.
Also, I'm not a class builder, but I did see in one of the builds that you can use Hetusol instead of Ornate Shadow (in that build).

The rest of your post is pretty valid, I hadn't thought about the set bonus 12 levels ahead - I'll be using that in my Archer!