My money is still on Rey being the sole survivor of the Jedi Camp, with Luke rescuing her, sealing up her memories and hiding her on Jakku until she was "ready" to take on the dark side. She would be unusually strong in the force or something which is why after Kylo fell Luke became concerned she might fall if she was allowed to continue her training without her doing something stupidly heroic beforehand.
Also I wonder if Luke is gonna feel very "grey jedi" in episode 8, I'm sure after the disaster that was the first academy Luke is gonna feel responsible, and scared of training others and as we all know fear is the path to the dark side. So maybe he dabbled in it or something. Maybe Luke will give us an oh shit moment in the next movie where he unleashes some force lightning.
I was 9 when I saw TPM, and I loved it. It had a kid in the movie, I was a kid, the kid did cool things just like the grown ups did, there were lightsabers and pod racing. Jar Jar was basically the kid humor of the late 90s too so he didn't even feel that out of place considering how many cartoons I watched.
The movie was literally built for 9 year old kids who were too distracted by the fun stuff to see the plot being a disaster.