I think that one of the problems with the LOTR is that a) there would be too much to choose from that you would no doubt offend people for leaving stuff out and b) the movies are already done and unlike spiderman are not going to be redone in 5-10 years (granted the hobbit is coming out)
I think with problem a), that situaiton could remedy itself based on public demand. Just like with Harry Potter. If the place is popular and the public wants more, I'm sure they could always expand the LOTR territory if the people wanted that. Also with b) yeah you do have a point that they probably won't be remade other than the Hobbit in the next 5-10 because it's not like spiderman or other superhero films where they can change the dynamics and storyline. If they remade it, I don't see how it could get any better than the trilogy we got from 01-03, other than maybe more visual effects. But even that, the battle of helm's deep in the two towers was probably the best battle I've ever seen in a movie. Anyway, I'm getting off-track.
I think the real dilemma with this kind of project would be a combination of the two issues you had mentioned, but for different reasons that you had stated. Take Harry Potter for example. For someone who hasn't read the books or seen the movies, a person can describe to them the main plot so that person can at least comprehend what's going on. Same goes for Avatar, and a majority of other movies as well. But the Lord of the Rings, you will truly have to do your homework for in order to enjoy the land. We all think it's a great idea because we have seen the movies/read the books, but for people going into the land cold so to speak, they are just gonna be lost. And with all the plot lines and detail, it's really difficult to describe the story to someone who has no experience. They really have to watch the movies for themselves in order to enjoy all of the detail that the land would most surely provide. And of course, going to Potter World without exposure to the movies/books, and having the plot explained to you in a few sentences is not going to provide the same experience as actually reading and watching the tale for yourself. But I think the Lord of the Rings is on a much grander scale in terms of that story-telling and to people without exposure, it's going to be confusing. In addition, I feel that LoTR is geared towards a more mature audience. I'm not talking about action and whatnot because Disney rides like Star Tours and Indy deal with violent action scenes. I'm talking about the story itself and how it would be in-depth for a younger audience. Again I might be wrong, but I didn't pick up a LoTR book until I was 14. And I didn't see the movies either until I was in my teens because in 01-03, Harry Potter and other novels were more appealing to my age group.
With that being said though I think this is a great idea, but I would put it in Hollywood Studios and not the AK. If this got a good backing by the company, I would just take out everything in the back left corner of DHS and let the imagination roam.