SPOILER ALERT, SPOILER ALERT, SPOILER ALERT, STOP READING IF YOU HAVEN'T SEEN THE MOVIE!!!
So, Kylo Ren's birth name is Ben. That's not right. Ben was Luke and Mara Jade's son. Han and Leia's kids were Jaina, Jacen and Anakin. So they screwed that up. They did get right that Solo's son became a Sith Lord, Jacen in fact: but his Sith name wasn't Kylo Ren, it was Darth Caedus. So again, a screw up. Had they kept just a *tiny* bit of consistency with the EU, it would have felt like a better movie. A simple name change is all it would have taken. Is that really that hard to ask?
There is no way a non-Force sensitive Stormtrooper could keep up with a Sith Lord in a lightsaber battle. That shit would be over in 3 seconds, Finn would be chopped in half. And a completely untrained Rey, who only discovered that she was even Force sensitive a few hours before the battle? Defeating a trained Sith Lord in lightsaber combat? Yeah, no. Sure, she would have lasted slightly longer than Finn. But she'd be dead in 12 seconds instead of 3.
Finally, yet another Death Star? Really? Ugh.
Now, for the good stuff: the movie looked fabulous. WAY, WAY better than the prequels. And I'm sure that had to do with actually filming it, like with literal film. Plus, no over the top CGI. There were physical models used for a lot of the shots, and that made all the difference.
The new characters are absolutely fabulous. LOVE them! Finn and Rey are going to really take the franchise somewhere for sure. And with Luke's training, Rey is going to be the new Jedi Master that we've all been waiting for. (Other than Anakin and Jaina Solo, which they've apparently ignored, that is) And BB-8 seriously kicks ass, no lie.
For the expected stuff:
I'm positive that Han was killed off at the request of Harrison Ford. He's getting too old, and wanted to be done with the series. Perfectly understandable, and I think they did it with class.