Interesting points.

I only add...
As you say, she has the money, he has the looks and the charm, and no money. Itīs a desirable match for her, who will gain freedom and a certain social consequence, and all the advantages of marriage. He being penniless will make him an agreeable enough husband, who will have some consideration for her when he...choses to take a break.
Itīs not probable that she has heard about Eliza or anything about his reputation. But by then some freedom in matters of the heart were allowed, so probably she didnīt bother in considering it.