That is a good analogy you've given, and I do believe yes that they are both not listening or understanding each other.

I also agree with the self-protection measure that Mary is feeling and intending is very human. I know I've felt like that before in my life.

I look forward to your further thoughts on the future chapters, but would like to discuss one thing you mentioned.

quote
"When I'm pondering on the relationship between Edmund and Mary it is tempting to follow a line of thought which loosely goes:-
It is good to be serious about religion/ethics and morality; Edmund is serious about his religion but Mary can take it or leave it; therefore Edmund is right and Mary is wrong. "

My take on it is not that Edmund is in the right just because he is religous.

I've previously mentioned in the GR the ideas, that Edmund is not disinclined for the clergy, he's going into it with the right feelings, and will be a good at it. He's not a hypocrite. A wastrel Tom Bertram, or Henry Crawford would make a bad clergyman. The stars are aligned for Edmund here. As a second son, his father has prepared a profession for him and he is content with it.

Leaving religion completely out of it, Edmund as second son has 3 choices of profession- clergy, law, or military.

Mary say ch. 22 “You ought to be in parliament, or you should have gone into the army ten years ago.”

For Edmund to have risen to distinction and have an income to match in the military, he would have had to join 10 years earlier.

So that leaves him with only 2 choices of profession, and only one of those will satisfy Mary.

I don't know how many options he would have had if he'd switched to law at this point in his life, but he doesn't see it as a viable option.
“That is not much to the purpose now; and as to my being in parliament, I believe I must wait till there is an especial assembly for the representation of younger sons who have little to live on. No, Miss Crawford,” he added, in a more serious tone, “there are distinctions which I should be miserable if I thought myself without any chance— absolutely without chance or possibility of obtaining— but they are of a different character.”
What he said there seems to imply he would have needed money before entering the profession. It would probably take time for him to work up to any point of distinction or to earn any money. He may not even wish to do anything like it.

It seems very unreasonable to demand or strongly encourage a loved one away from the profession they are happy to enter- in any day and age.

The only reasons I can think of where it would be right to encourage a spouse to change profession is if it makes them unhappy, or they are crossing over into unethical, immoral, or illegal as part of it.

Edmund, with his limited choices, is extremely lucky that he has a profession ready made that he is happy to do, and it will provide him with a good income from the get go.

Edmund is wrong to continue to court her so steadily when she keeps saying that a clergyman is unacceptable to her. But ever blind, he continues to hope and rationalizes that she's joking. ch 27
“she says it is to be the last time that she ever will dance with me. She is not serious. I think, I hope, I am sure she is not serious; but I would rather not hear it. She never has danced with a clergyman, she says, and she never will. ... to–morrow I leave home.”

Lastly, imagine how his father would feel if he were to suddenly say that he wants to go into the law, when his father had been preparing this profession for him all along, Edmund was on the verge of taking orders, and Edmund had always been content with it.