That is a good movie to watch if you need to know how to make a bad movie.
That is a good movie to watch for examples of actors and actresses trying their best to improve a bad movie. At times they succeed!
That is a good movie to watch for an example of how annoying and bad a sound track can be.
I could go on, but there would be spoilers.
I'm a little late to the party as I just watched the movie last night and remembered there was a thread on it here. Agree with what you have said. Also...
It is a movie to watch if you want to see the most unrealistic court scenes since Perry Mason.
It is a movie to watch if you want to see the most incompetent gangsters you will ever see with the most unlikeliest mafia boss in the history of cinema.
It is a movie to watch if you like stories about indestructible women, like Supergirl.
Still, I was entertained.
As to the worst courtroom scenes, and to answer the OP's question about accuracy [very slight spoilers]
There is a scene where a lawyer representing the elderly woman who had been forced into assisted living presents an affidavit to the court. The affidavit is from an employee of the doctor that signed the order stating the woman has dementia and needed a legal guardian. Basically, the affidavit states the doctor is part of a long con game bilking elderly people out of their property. The legal guardian (Rosamund Pike's character, acting as her own attorney) objects to the affidavit by saying the employee was fired by the doctor for incompetence and for being "worthless". The judge says he knows this ex-employee and that she is indeed, "worthless." The affidavit is not allowed.
I'm having a hard time coming up with a better definition of hearsay than that exchange.
The title, "I Care A Lot" is something no one has ever said in the history of the world about any of the characters in this movie.