I've been re-reading Lover's Vows, and it is really fascinating how its themes have been appropriated by Jane Austen for her purposes. I have found some interesting material in Acts I and II so far. I apologise for repeating some of your quotes, but I wanted to expand on them a little more.

Act I

Agatha [Maria] has just told her son, Frederick [Henry] that he is natural born, and says this about her seduction: I was intoxicated by the fervent caresses of a young, inexperienced, capricious man, and did not recover from the delirium till it was too late.

How apt a quotation for Maria to speak! Maria, who had become engaged to Mr. Rushworth without any passion, love, or even respect for him, was intoxicated by the gallantry of a young, capricious, albeit experienced man of the world, Henry. However, unlike Agatha, it appears that she has recovered from the delirium before it was too late, and has gained her original objective- material possessions, and a good status in society.

Act II, Scene II

The Baron [Mr. Yates] has invited Count Cassel [Mr. Rushworth] to his castle, hoping that he and his daughter, Amelia [Mary], would make a match of it. It appears, however, that the Count is really not "all that". Here are the Baron's thoughts on his intended son-in-law: And am I after all to have an ape for a son-in-law? No, I shall not be in a hurry—I love my daughter too well. We must be better acquainted before I give her to him. ... The poor girl might, in thoughtlessness, say yes, and afterwards be miserable.

Hmm... looks pretty much like Sir Thomas' thoughts on Maria's engagement to Mr. Rushworth.

Mr. Anhalt [Edmund] is a young clergy man who has been a tutor to Amelia, and Amelia describes a dream she had the night before to her father: I dreamt we were all still in France, and he, my tutor, just going to take his leave of us for ever—I 'woke with the fright, and found my eyes full of tears.

Now, Fanny appears to fit into the mold here better than Mary. After all, Edmund has been a mentor to her, and she is on the brink of losing him forever to Mary.

Here is a quote from the Baron that would easily apply to Henry.
The Baron discusses going shooting with Count Cassel: I am not particular what game I pursue.—I have an old gun; it does not look fine; But I can always bring down my bird.

Zing!