I quite agree with your take on it. In fact, a gentleman's code of the times might require that Bingley offer for Jane due to the nature of the attentions he paid. It is actually an indictment to some extent of Mr. Bennet that he did not demand more appropriate behaviour or require that Bingley declare himself.
I agree that Austen wants us to like Bingley - and for the toimes, he was a gentleman. Whereas Darcy would not show his interest to avoid creating expectatiopns, Bingley ignored expectations altogether in showing his interest. I believe he danced three sets with Jane at the Ball and his presence inhibited other men from approaching her. Both are tantamount to the behaviour of an engaged couple even in country society - particularly at a formal event like a ball.
