Star Wars: The Force Awakens - 7 Biggest Unanswered Questions
So, yeah, about Luke...
A Star Wars movie leaving a few things unanswered is nothing new: back in 1999 everyone was going crazy over why Qui-Gon Jinn's body didn't disappear like the Jedi in the original trilogy and how on Yavin midichlorians worked; in 1980 playgrounds were full of children debating if Darth Vader had actually told Luke the truth about his parentage; and even earlier, in 1977, the first movie in the series presented innumerable questions, from what the Clone Wars were to why the Lars clan drank blue milk.
That's the beauty of Star Wars, really; it's a world so vast and ripe for exploration we can't help but imagine what's lurking just out of frame, let alone deal with the big things raised explicitly. And, being so in the spirit of Star Wars it is essentially the movie equivalent of Force ghost, the same is true of The Force Awakens.
We obviously had a lot of questions going into Episode VII, and while most (not all - see several points of this list actually) were answered, plenty more were asked. Some will no doubt be addressed down the line in the rest of the trilogy, but don't be surprised if Disney ignores some more than George Lucas does The Holiday Special.
WARNING: This list contains both spoilers and intense nitpicking (rest assured, I did like the movie).