Continuity mistake: It's raining heavily all night, but when Burnham goes up on the roof to look for a way in, you can no longer hear the rain falling on the window. Later on, we see the rain falling heavily again.
Suggested correction: Rain does that all the time. Starts and stops, drizzles and pours. This is not a mistake, but rather how Mother Nature works.
Stupidity: When the police turn up the first time the mother lies to them to get them to go away but the burglars can't hear the conversation. She could have told them exactly what was happening and that she had to make it look like she'd got rid of them. She could have then smashed all the cameras and just let them in.
Suggested correction: This was a character decision, and a completely understandable one. Her daughter was being held hostage in the panic room. She decided to cooperate with their demands for the safety of her daughter. Your idea is a solid one, but she simply did not think of it in her state of mind. She opted to get rid of the police, and her decision is not a movie mistake.
Other mistake: Raoul told Junior he wanted ⅓ of whatever's in the panic room, but Junior told Burnham only the two of them (Junior and Burnham) knew the money was in there.
Suggested correction: Like you said, Raoul stated he wanted 1/3rd of *whatever* is in that room. He doesn't know what's in there, but he would assume it would be valuable.
Other mistake: According to the cops at the door, Meg's husband revealed to them that Meg said "There are three" on the phone before the line was cut off. However, earlier in the film during the call, Meg said "There are three men..." and then the line was cut by Burnham. The husband would have heard the word "men" as well to give to the cops.
Suggested correction: Steven (the husband) was just woken up in the middle of the night to a frantic phone call from his wife. Very possible he did not hear, or simply did not recall hearing that one word.