Not really. Since movies are not filmed in sequence, the usual clues that an astute eye might pick up (lighting, shadows, beard growth) won’t help. Sometimes actors in a scene are not even filmed at the same time, a director may decide the next day to get a few closeups of dialogue instead of showing the actors talking to each other.

Sometimes you can see outtakes of scenes. Outtakes are when the actors mess up and then they laugh or get mad or whatever. It can be amusing. Probably the majority of them are boring but they’ll clip the funny ones and make them into a video. Sometimes TV shows will have the outtakes at the end of the show.

You might hear that info if you get the director’s cut of a video and turn on the commentary or do research on the film. It won’t be obvious from just a viewing of the film.

Only if you see the very first part of the take where the clap board is employed. (“a pair of hinged boards one of which has a slate with data identifying a piece of film and which are banged together in front of a motion picture camera at the start of a take to facilitate editing – also called a clapper board ” -from Merriam-Webster’s Collegiate Dictionary, 11th ed.) Also, FYI, the banging of the clapboard synchronized the sound of the take to the film reel. This bit of film usually only makes it to the editing floor, then discarded.

Nope.