No the writer's ideas is something else, no context. The writer's idea is what he was thinking when he was writing this but you have explain it without context. Instead talk about the theme of the play: class, gender, socialism, age, responsibility and guilt. Depending on what the question is asking. For Mr Birling you can talk about Reputation and Capitalist Ideas against Socialism. Or for the Inspector and his message at the end you can link to Class, Socialism, Guilt and Responsibility. That is what it is meant by the writers ideas