Again, I don't care so much whether they were JJ mystery boxes or not, Rian just did basically the worst things he could with any of them, which was basically pretty much ignoring or discarding any of them. To say he set up Rey as a supreme character is exaggerating, Rian dialed that shit up to 11 compared to JJ. Because she "beat" a still spoiled brat apprentice who had taken a Chewie bowcaster shot and already fought Finn? Peanuts compared to what came after.
I'm not a fan of how Han's character was portrayed, but it also could make perfect sense, unless you're so tied to the reformed smuggler with a heart of gold version of Han Solo you can't imagine anything else.
First movie wasn't great by any stretch, but it at least had some potential as a beginning to a trilogy. He opened the door for a lot of stuff in the second one, but Rian should get 90%+ of the blame for the extremely shitty directions he chose.