Thanks for such a detailed review, really appreciate it.
1) Yes, that's probably the main danger spot, that players can kinda get lost in the story as it gets bigger and they explore more and more. I've partially tried to deal with it using "remember" mechanic, that allows you to "save" some words to see their meanings anytime and restart the sequnece from there. Was this mechanic clear or not that much actually?
The fading was made to help players see what they've unlocked by clicking before it gets lost inside the other text, but the timing may really be a bit too long.
Thanks for the review again!