WOW! INCREDIBLE MOVIE! To me, this was one of those movies where you wonder when it's going to end, not because you want it to end, but because you logically know it's only two hours long and it feels like a LOT has happened.
So on to some points here.
Yes, there were some contrivances. I guess the biggest is Han and Chewie just happening to be in orbit of Jakku while the First Order was hunting Poe. As for this one eh, coincidences happen, life is full of them. Some of us believe in divine intervention for some of them in our lives. Now if Rey really is a Skywalker then her finding him could be explained as the will of the force, or even just the will of Luke, subtly influencing events through the force from light-years away.
Rey running into Finn/Han/Chewie. Yes, she's on a planet-sized battlestation (that's no planet?...Except it actually is!) so the chances of her running into them are tiny. I admit that, but it was fun anyways.
Kylo Ren. I agree, removing his mask to reveal...a kid with big hair...might be a mistake, but at least he's not a whiny kid named Anakin... As another poster said, he's not so menacing now, and why the mask to begin with?
Also, he is irredeemable to me. You kill Luke, fine. Leia, fine. C-3PO, fine. But kill Han Solo, Chewie or R2-D2? I WILL DANCE ON YOUR GRAVE AFTER PERSONALLY ENDING YOU, THEN DIGGING IT MYSELF, THEN DUMPING YOU IN THERE! (note: the previous is intended strictly from an in-universe perspective. I intend no harm whatsoever to any actors, writers or directors and in fact congratulate them on this very gutsy creative decision to kill off such a well-liked and dynamic character, and how they accomplished that).
I think I'm going with a third option on Dbeachy1's theories on Kylo killing Han. It's possible that there never was any conflict, and he simply needed to appear as if there was in order to let Han lower his defenses.
Starkiller base was at least a little over the top. Aside from Abrams's "space not so big" thing he seems to have problems with, it also feels like a contrivance that they even knew about it. However, it doesn't seem like a logical next-step from the two Death Stars. A more logical step would be a more compact superlaser on something more resembling a traditional starship, I believe some expanded universe material explored this angle. Basically something that doesn't lumber along like the Death Stars, but something quicker, and more able to "sneak up" on you. The star-fuel thing could still even be a part of it.
An interesting thing I noticed is that the First Order seems to utilize the same recruitment techniques the prequel Jedi did, they take kids and raise them in their ways. It's an interesting parallel, that I don't think is just writer-coincidence, that I hope is explored.
A friend that watched this with me also wondered if this might be an opening for a return of the Calrissian! It would be interesting, though maybe add one-too-many contrivances on top of what we already have, and it would be harder to handwave it away with the force since Lando wasn't particularly force-sensitive that I know of.
I do wish there had been just a touch more galactic politics. Not the over the top let's-open-our-movie-with-a-conference-on-trade-taxation thing Phantom Menace did, but just a better explanation of what the Republic is doing and why the entire Republic isn't involved in dealing with a very real threat. It felt too much like the Rebellion era again which the movie made clear we've moved past. I'm wondering if this isn't a subtle play on the U.S. vs. ISIS (yes, I know getting close to Basement territory, may open a thread there for deeper discussion on this point). Where a threat is ignored in all meaningful ways until they do something drastic. I'm not as sold on that theory as I was on Revenge of the Sith being a swipe at Bush, but I can't help but draw the parallels.
Ok, I've poked at this movie enough. Let's get to what I really liked. As I opened with, the movie was satisfyingly full. Most of the slow moments were just slow enough at just the right moments, the action was well-paced and flowed naturally from the plot rather than being forced. The music was second to none.
I love Rey and Finn, and think they along with Poe can easily be the next Luke-Leia-Han trio. Each filling different roles of course, but the same kind of tight bond and camaraderie that drove the three from midway through 4 through the end of 6.
Han Solo. Yes, it stung. But if it had to be done, it was done well, and the emotion in Chewie, Rey, Finn and Leia was incredible! That hug between Leia and Rey was intense. The end scene with Luke was similarly intense as someone above says. The emotion all over was well-done.
The Millennium Falcon. 'nuff said. Ok, not really, I do have something to say. Such an incredible re-introduction, definite call back to ANH with Luke calling it a piece of junk, then immediately outclassing everything thrown against it. It will be bittersweet to see on subsequent watchings, but as I said months ago: "Chewie, we're home" just kinda says it all.
The lightsaber combat. It struck a good chord between the slow "fencing" of the original trilogy, and the CGI-nuts stunts of the prequels. Ok, some of that will change if Rey and/or Finn receive "formal" training, but Kylo presumably had training.
I'm sure there's more, but that's all I can remember. I may try and see the Imax version later this week and be able to pick out details I might have missed. I can't think of any other movie that's made me want to immediately re-watch it, so that right there says a lot.
[EDIT]
WOW, ok, this is another reason I know this movie is awesome. I completely neglected two areas which usually stand out to me most: humor and visuals.
The humor was perfect. Han's lines were exactly what you would expect from someone having gone through all he apparently did.
The visuals. My gosh they were georgeous! I think the scene that did it for me was the TIE fighters silhouetted against the sun. It reminded me strongly of some scenes from Top Gun, which was decidedly not SciFi and helped bring the "realism" up a good few notches.
Something else that occurred to me after I hit post. Why Ben? The name I mean. Ben Kenobi is what I would expect, and the EU stuff confirms, Luke to name his offspring. Ben shouldn't have a particular connection to the Organa-Solo family, Bail Organa knew him as Obi-Wan, not Ben. Maybe he really is Luke's somehow? Maybe he's biologically Leia and Han's, but Luke raised him more than they did? Really to isolate yourself like that requires a deeper personal connection than your nephew even if you were training him.