How has Priestly stuctured the text to interest the audience in this section of the play?

In the beginning of the play, Priestly has structured the text to draw in the audience. From the start, the audience is a part of the Birlings intimate family dinner, we know it's a celebration, we also quickly become aware that something more is going on. The charaters are cordial, social, and here and there, they indulge in a bit of banter. Is the banter meant to be witty? Or is it meant to be cutting? We're not really sure, thus, we lean in a bit and take a closer look because we're not really sure what's wrong.... at least until the Inspector calls.

The opening is significant because it becomes the binary opposte of the atmosphere/mood of the evening later on. The family are close, sharing food, drink and jokes and having a good time in general. The tone shifts when the doorbell rings and a "large 'man'" appears to them. Note, he shows them no ID, no warrant card and all he brings with him is a single photograph - or so it seems. Slowly, the Inspector reveals and expresses the divisions and secrets between the other characters. He has ruined their evening and Gerald and Sheila's relationship. They go from being prepared to commit themselves to each other, to feeling changed by the presence of the Inspector. We never find if they work out the differences as the play is abruptly ended by a phone call. Personally, I question whether the ending used was the best way Priestley could have ended the play, as it leaves so many questions floating around in the audience's head. Ultimately, we never actually learn much from the play. We learn they character knew a girl and a girl died at the end. The Inspector was a fake. I think the ending almost ruins the play as the plot generates so many questions, but they never get answered and so I certainly think the ending works to Priestley's disadvantage. In fact, the family celebration might as well have been left alone but really, when the character have obtained all this new information, they don't know what to do with it, except know they can't go back to how they were. We don't find out if criminal theft charges were brought against Eric - in fact we never even found out if he went to prison or paid back the money. We never learn if it was Eva Smith died, if her baby died, or it was someone else who died. Do you see my point? There are just too many unanswered questions for the ending to be considered an effective one and so the audience, frankly, are left with a huge anti-climatic and rather disappointing ending. The police officer that is said too be on his way over at the end never even makes it to the house before the ending. It is all rather pointless. Using this insight, look at the beggining of the play in Act One. Is any of that left at the end? I don't really think so. Mr and Mrs Birling and Gerald try and get on and move forward, perhaps showing their maturity, however Sheila and Eric who we know can be extremely immature (Sheila at Milward's and the way she talks to her parents and Eric's irresponsible relationship with Eva/Daisy and his drinking problem) do not. In fact they feel as separated from the family as ever. In the end, no one gets their comeuppance and really nothing happens. So many questions... Hope it was a little helpful, your question can only really be answered if you have a clear understanding of the events in the middle of the play and the ending, which I have tried to give. If you've got any more questions have a look at some of my other answers on the AIC Q&A page or just ask and I'll answer, although I can't say how quick my response will be. Sometimes, minutes, next day, a week or sometimes I don't check on here for like a month. But I promise if you've got a question it will be answered. Haha.