If by Bingley's "consequence" you mean his social standing, then I can't really answer your question on that. We simply don't know the social standing of those at the assembly, except for a few families, since they do not come into the story. I think the Bennets' social standing was above the Bingleys', but no one's at the assembly arguably came near Darcy's. I question whether if someone of higher social standing (than the Bennets) were there he would dance with the ladies of the party, unless he was already acquainted with them.

I'm not sure what Darcy meant by saying a woman must be particularly known to him before it would not be a pain for him to dance with her. Since he converses so little throughout most of the novel, his idea may not include having had extensive conversation. Or he may have been exaggerating his stance. But I do think Darcy was ready to dance with Lizzy at Lucas Lodge, or he could have bowed out as he did before, and as Lizzy did in this instance. I don't think he was planning on asking her to dance, because they were not at a ball. He wanted to converse with her. He was ready to be teased by her without offense, which I think speaks some kind of familiarity.

Yes, I think Darcy is blind to Lizzy's beauty at the beginning because they are strangers. The longer he knows her, the more beautiful he finds her. Something has changed, and I believe it is his growing familiarity with her. As for as her character, he could not have known much about it at the time of the insult, nor did he criticize it.