i mean english lit is level based, and relies on the fact that you do consistently on all essays to get your grade.
while I may not be able to comment a clear level/ mark. i can give some feedback.
In your first paragraph, you need to explain the wider intentions o priestly. why make Mr birling look daft towards us the audience. is it for the same of it, or a deeper meaning? I'll let you come up with the idea, but think what he is a microcosm of and what he's trying to tout in this play. to access higher grades, put in your own opinion that may differ from school, after all this is an opinion-based subject. and having that extra perhaps shows you are thinking. lets say with Mr birling in act 1 you can provide evidence of him being a victim to what he praises as he is not at the top, but seeks to have his legacy be there in the form of his progeny ie the marriage with the Crofts. then use the correct quotes and you have a pretty good point with is different to what the "average" student who is also studying this book.
this paragraph above feels horrendous as I was writing it, but I hope it gets a general idea to you.
so focus more on the writer's intention as what difference would it make in Mr birling was right on his assumptions, is there a knock-on effect, I recall that this speech generally in the story had no real place ( if it was real). remember Mr birling is a bourgeois he is almost at the top but will never be there. so he hopes for the next best thing. ( as a separate point)
you could also reference history with the historical labour win which allowed labour to make radical changes to the system, which could in turn infer that with low costs high prices, he's trying to show greed from this new money type of people, and hence after the war this audience wishes to see justice and equality with workers.
i personally don't really like this question as I would prefer to maybe talk about the change each character procures by the inspector but yeah and how that has changed. for example, last year's gcse question on women was fairly interesting.