Other mistake: In Finn's attempted sacrifice, there are plenty of logical inconsistencies. First, Rose's pod is to the side or behind Finn, but manages to beat Finn's pod to the cannon. The collision had a similarly high chance of killing Finn as would ramming the cannon. Finn then carries Rose back to the hideout faster than it took the speeder pods to reach the cannon.
Suggested correction: She beat Finn's pod because she was going full speed. The force from the shock waves slowed Finn down. Crashing saved Finns life. He was going to crash to burn inside the laser if she hadn't saved him.
The other speeders were ordered to retreat. Finn was going full speed, so as to maximize damage to the cannon.
Other mistake: Maz Kanata's message is somehow not intercepted by the First Order. It is also projected from various angles and follows her around during her shootout, making one question who is filming the call in the first place?
Suggested correction: Since this particular technology is not fully understood (and is fictional, to boot), this "mistake" is based upon pure speculation and should be disregarded.
Disrupting transmissions has existed in the Star Wars universe chronologically as early as Episode 1. The First Order had the means to do this but did not. If they were at all competent, they would have disrupted all Resistance transmissions.
Given the training remote seen in the first move it would be rather easy to say how Maz was able to "film" the call.
True, However, those droids were not subjected to a battle when they are shown in Episode 1. So filming the call is plausible. However, there is no way the call should have gotten to the Resistance without it being disrupted or intercepted by the First Order.
Again, fictional technology, and no firmly established rules as to how it works; the same could be said of pretty much all the tech depicted within the SW films (lightsabers, droids, hyperdrive, etc). Probably best just to go with "suspension of disbelief" here.
But you are wrong. There are established rules on how certain technologies operate in Star Wars through examples in the previous movies, TV shows, etc. Even if we do not know how they work, we know what they do. Disrupting communications and transmissions is a big plot line used in Episode 1, chronologically the earliest Star Wars film. In Return of the Jedi, the Empire jams the Rebels sensors so they do not know if the shield is up or down. The technology exist and the First Order should have used it on the Resistance.
The technology existed forty years ago. Finding a way to thwart the jamming would be a high priority of the rebels' scientists and engineers.
That's an assumption. If that is the case, because of the previous films it needs to be explained in the movie. Otherwise, it goes against established canon, which is a continuity error. You could also just as easily say the First Order developed an unstoppable way to intercept transmissions in those 40 years. It is also an assumption that thwarting transmission jamming would be the Resistance's highest priority. If anything, technology has not progressed very far in this trilogy as the FO is still fighting with TIE Fighters and the Resistance still uses X-Wings.
Other mistake: When Luke is reunited with R2D2 aboard the Millennium Falcon, R2 plays the original hologram of Princess Leia from A New Hope. It is being displayed on the floor, to Luke's right. He tells R2-D2 that was a cheap move, and R2-D2 turns his head to look at Luke. Problem is, the device that he is using to project the image is on the part of his head that turns. We see the beam of light move when R2 moves his head, but when Luke turns his attention back to the hologram, it is still in the same place.
