Lovely little experience, here are my thoughts:
I managed to get through with no brute-forcing or wild guessing, which was very satisfying. Poring through documents reveals a very interesting narrative, which is reflected in the family tree. I was a bit annoyed by how difficult it was to discover the last few documents, figuring out the feature of unclicked words was helpful, and highlighting the specific ones would be too much, but I think that unclicked words should account for ones searched on other documents.
The alternate language was a really cool concept, you can learn a lot about their culture through the word construction, and it's a helpful layer on top of the documents that creates additional depth to the puzzles. I did think the end was a bit abrupt, I felt the central question was who the rightful heir was, and I didn't get a chance to work it out. You already know about the locking in by three things, I definitely agree there needs to be something there that indicates which have been affirmed.
I was looking forward to a new puzzle from you, I'll be eagerly anticipating future work.