I care that JJ wrote a story without any answers to these questions.

This complaint always surprises me because what you are complaining about is the process by which every story is created.

If you take your most favorite piece of episodic entertainment, whether it's a movie series, TV series, sequence of novels, etc.--in every case if you go back and research the creative process, you will find that it worked the same way that the ST is working.

Authors a) don't know the entire story when they start, b) intentionally don't explain everything at the beginning, c) change things along the way, and d) go back and mine the details of previous works to create "connections" to the new work.

If you want to see Lucas building a "mystery box", watch the scene in Obi Wan's house in ANH. The number of knowing looks Obi Wan throws around, the off-hand references to the Force, the Old Republic, the Jedi Knights, the Clone Wars, etc... there was almost no backstory to any of that when that movie was made. It was in the script because Lucas wanted to create the sense of a larger universe, and he thought those would seem interesting. Same with Vader's lines about the Force in ANH.

Most of what we think about Star Wars didn't show up until ESB or later. You can move objects with the Force? Not in ANH. Darth Vader is Luke's dad? Not until late in the writing process for ESB. Leia is Luke's sister? Not until they were writing ROTJ. Anakin Skywalker was the "Chosen One"? Not until TPM.