I don't see how Han finding the Falcon was that much of an "incredible" coincidence. He said in the movie, "Did you think finding the Falcon was an accident? You were screaming your transponder signal. If we can find you the First Order can find you" or something like that. It would be a huge and obnoxious coincidence had Han been on a mission for the Resistance when he stumbled across the Falcon but it's clear, at least from my perspective watching the movie, that Han and Chewie spent their free time looking for it and they knew what general region of the galaxy it probably was in.
Somehow, the First Order, despite having a star destroyer parked overhead, failed to notice or care that a light freighter which had just blasted its way out of their target area and taken out a couple of their fighters has left the area.
The Falcon had just left Jakku, and hadn't gone to lightspeed yet, so it was still rather close to Jakku.
Just minutes later, Han shows up. Even if they had been in the next system over and heard a transponder signal, it should've taken them longer than that to get to them. Also apparently the First Order doesn't notice or care that some big freighter is picking up that light freighter which escaped from them.
When told the Falcon had been on Jakku, Han acts
surprised that it was there, even though they must basically still be in orbit of Jakku at this point, and apparently Han must've been
waiting over Jakku for them in order for this to make any sense.
Also, somehow Finn (who's been living with First Order equipment his whole life) thinks that Han's freighter is a First Order ship capturing them.
The sad part is, this scene could make SO MUCH MORE sense with only a small change and not much more screen time. The Falcon heads for space, pursued by a handful of fighters. The star destroyer is approaching, they need to go to hyperspace
now and can't wait to calculate new coordinates. Conveniently, there's a set of coordinates already in the navicomputer, so they jump at the last second.
A few (in-universe) hours later, they come tumbling out of hyperspace, and something's broken and leaking and they have to fix it before they can jump again.
Now Han and Chewie show up. Bam. Everything makes sense. Han and Chewie got the transponder signal (either telling them where the ship would be going, or they'd locked the navicomputer to only be able to go to that one place, or hell, maybe even it was a two-way thing (Falcon contacted them when it booted up, they remotely locked it to those coordinates). This is now my headcanon for that scene, next time I see the movie.
Since when has space ever been big in a SW movie? Or a JJ movie?
All the other movies made space seem pretty big. Vastly different systems separated by significant amounts of travel time, and you sure as hell couldn't see "the entire republic" getting destroyed from some watering hole elsewhere in the galaxy.
It's not a SW thing, it's a JJ thing. The man should not be allowed anywhere near space movies ever again.
But, apparently, the unwashed masses are largely too dumb to realize what's wrong with the movie, which is why it has a 95% on Rotten Tomatoes. If no one else beats me to it, maybe I'll have to make an hour-long review (a la the RLM prequel reviews, but without the weird interlude scenes) talking about all the problems.