What are three ways Eric is significant in An Inspector Calls?

Eric, the Birling's son, is significant to the play in the following ways:
First, Eric is an alcoholic, which undermines the family's claim to be good, upstanding, middle-class Edwardian people.
Second, he has an affair with the down and out Eva, another black mark against the Birling family, as it represents pre-marital sex and takes advantage of a young woman who is in desperate circumstances and needs the money Eric can provide for her.
Third, and most devastating, Eric is the father of Eva's child. When Eva goes to the charitable committee of which Sybil Birling, Eric's mother, is chair, Sybil coldly refuses to help the desperate woman. Sybil even states that the father of the child should be exposed to shame and have his identity made public, showing her hypocrisy, as she would never have said that had she known her son was the culprit. It is beyond Sybil to be able to imagine her own son stole to support Eva and made her pregnant. Of course, when she does find out, she wants to cover it up.
The elder Birlings want to distance themselves from the people suffering in their society and say it has nothing to do with them. Their son Eric's close involvement with Eva shows, however, that the suffering of the lower classes is intimately connected to them.