When I first read P&P many years ago I though that Darcy was proud and disagreeable and I believed that he was going to be the villain of the novel. I believed the story of Wickham. Now I think that one thing (Darcy being proud) do not necessarily imply the other (not giving the living to W).

> I think the importance of a gentleman being both attentive and pleasing in manner cannot be undervalued when looking at how Darcy and Wickham are judged by Lizzy and all of Meryton.

I suppose that being attentive would be important but I suppose that there would be another things that made a gentleman. (I don't say "being a gentleman by birth"). Perhaps Darcy has these other things, but lacks in being attentive. Imagine that Darcy were amiable and danced with all the girls, and didn't despise people, but were an immoral person. Would he still be a gentleman?

You said below that it was more than W being handsome and amiable that made E believe him. In chapter 16,

"This is quite shocking! -- He deserves to be publicly disgraced."
"Some time or other he will be -- but it shall not be by me. Till I can forget his father, I can never defy or expose him."
Elizabeth honoured him for such feelings, and thought him handsomer than ever as he expressed them.

and later

Elizabeth was again deep in thought, and after a time exclaimed, "To treat in such a manner the godson, the friend, the favourite of his father!" -- She could have added, "A young man too, like you, whose very countenance may vouch for your being amiable" -- but she contented herself with, "And one, too, who had probably been his own companion from childhood, connected together, as I think you said, in the closest manner!"