I disagree. I think it worked just fine as a movie.
So if that was a standalone movie, you'd be ok with hearing about this Luke Skywalker and how important he is to have it just end with that scene?
What would you know about Luke? He set up some school, screwed it up and ran into hiding ... therefore we need him to stop ... what? Starkiller base? Nope.
Seven not only absolutely needs 1 to 6 to work, but without question needs at least an 8.
Finn was simply goofball with little value. Don't tell me how the janitor (that was out on the most important mission for some odd reason) knew that you need to upset the flux capacitor or how to blow it up and what it would mean was vital to the story in anyway.
Brought Rey into the alliance, I mean resistance? Nope. That was BB8 and running from the Empire, I mean First Order. He told her where the base was. Wait, that was BB8. Oh, he said shields are bad. Did they not know that using ... an IQ above mentally incompetent?
As the movie stands on its own, it will rate low for me. It really needs the rest of the saga to give it any meaning or direction. It is extremely easy to pick apart, so I am assuming this has more to do with the setup stages and the "hiding" of plot points and true character backgrounds. Therefore, I'm not going say my questions are actual problems as of this point.