I completely agree with everything you've said. I think this is definitely a play through once in 15-20 hours and then never go back to.
I understand why people don't feel like they know what is going on, but if you're struggling just look at the map legend and it should clear up what all the icons over the place mean.
One thing that dissapointed me a bit, and perhaps this is my lack of knowledge of LOTR, is that I was hoping for a game where there were towns and villages with friendly NPC people in it, a bit more like an RPG. This is completely my own fault for not knowing this as I clearly didn't read enough into the game, this is just what I assumed it would be.
I am enjoying it though, but I'm glad I didn't buy it at full price (a friend did, and we game share on Xbox One).
As for the Nemesis system, I LOVE it. Imagine this kind of thing in a game like GTA or something.