Other mistake: As the Enterprise is fleeing from Q, it peaks around Warp 9.6 which according to the fact books, translates to around 1000c in sidereal space. Also according to the fact books, the saucer section is not capable of sustained Warp flight on its own. Also, at the beginning of The Chase scene, the Enterprise is on course to Farpoint, Q's fence is perpendicular to it. The Enterprise does at least a 90°+ turn beginning her escape maneuver prior to separation, so it is definitely not flying past Farpoint during The Chase. Still the saucer section somehow makes it to Farpoint a mere 51 minutes after the engine section. There's no evidence at all in the dialog that it was Q's doing.
Other mistake: In this episode, in Riker's memory, the encounter between him and Quinn is re-lived. As Quinn starts to attack Riker, you can see Riker's stunt double's face, and tell that it's Quinn's stunt double, as the hair is smooth, not styled. Also, Riker is a few inches taller than Quinn, but in the onset of the attack, they're equal heights.
Other mistake: Toward the end, Beverly gets in the turbo lift to go to Engineering. As it starts, you see the lights to her left strobe top down. This is to indicate movement. However, since the lift was at the bridge level, the lights should have gone from bottom up, showing that the lift is going down.
Other mistake: After the report that Picard is close to death, the scene shifts to a close up of La Forge's hand turning on controls. If you look closely, you can see that both panels are re-purposed CANX-23429 remote control units. The markings are for volume, radio, transmitter, receiver, phone jacks and a microphone jack.
Other mistake: When Scotty goes to the holodeck to visit the original Enterprise, the computer tells him there are 5 Federation vessels with that name. (NX-01 served before the founding of the Federation so this is technically correct.) Scotty specifies NCC-1701, "no A, B, C or D." The computer then tells him the program is ready. The computer should have asked him if he wanted pre or post refit NCC-1701. The ship we see in the Original Series was rebuilt/refit into the ship we see in The Motion Picture.
Other mistake: While down in the pit Geordi makes a couple of spikes to climb out with. When the phaser beam is melting the ore, the metal goes molten about two inches in front of the beam. Also, the spikes are rounded, like handles. The molds he made would have left a flat side.
Other mistake: One of the physical appearances Lal considers adopting is an Andorian female with green skin. In the Trek universe, Andorians invariably have blue skin (the Aenar are a variant of the Andorian race but are depicted with bluish-white skin, still not green). And while other humanoid races have been portrayed with different skin tones, there are some races that have only one skin hue. (ie, Andorians are always blue, Orions are always green, Ferengi are always light orange.) It is highly unlikely she or Data designed it with different skin as Data wants her to fit in, and Troi makes no mention of it.