1) Space is three dimensional. The ONLY way the explosion of the drive section could knock the saucer into the planet's atmosphere is if it was positioned between the drive and the planet. The drive section was parallel to the planet when they started the evacuation. So basically Troi had to specifically turn the ship TOWARD the planet. That's not just a "nudge" in the wrong direction.
2) Yes, really. Those windows are expected to survive weapon blasts, crashes and other such trauma in space. Then they break when there's a crash scene? There's no reason for that but lack of continuity and that someone on the set thought it would be "cool."
3) Yes, the did have to evacuate the crew. That's not what I was talking about. I was talking about the civilians. There were tons of them being moved in that scene, especially that little dramatic scene of the girl dropping her bear. The whole point of a separable ship is to keep the civilians safe in crisis situations. That means they should all be in the saucer. But evacuating the crew wouldn't be "dramatic" so yeah.
Certainly these aren't the three biggest flaws in the movie, but they are relevant to this scene which is what the thread is about. Even something simple as this scene they made obvious mistakes.