First time poster here on the site! My dream for the LOTR area would be one that takes from the Hogsmede/Hogwarts formula of having a food and retail area that leads to the main E-Ticket attraction. In this case, Hobbiton would be a fantastic entrance to the land, with a Rivendell structure at the back of the land for you to discover.
In Hobbiton: Aside from the Green Dragon Inn and some shops inset into the hills of Bag End, the ride system I've not seen mentioned - but that would be really appreciated in this park given the need for dark rides - would be a relatively simple POTC/Na'vi RJ style boat ride through the shire at night during Bilbo's birthday. Queue through Bilbo's house! And on the ride, give us a "cocktail party" re-rideable experience with lots of dialogue and gags around the tables of food and drink, songs being sung, Gandalf wrangling mischievous Hobbits, ending with a big fireworks display. All vibes. The ride could then spit you out in the transition path between Hobbiton and Rivendell, which leads you to a big reveal.
If, in story terms, the transition path is the start of your "journey across middle earth" you could have some Ringwraith action of some kind in the trees - either live actors or something even more themed-in.
And then in Rivendell, Universal can pull out their bread-and-butter E-Ticket as you say, a KUKA arm thing with a bit more thrill and peril to it. Queue past the broken sword and the circle of chairs, etc.
This would be a full package land though and it'd be interesting to see if there's enough room for it. I sort of doubt that Universal would be brave enough to do boat ride like that, though.