Can Mac Mail send me a read receipt for an email?

Nope. Only certain email service providers offer that feature. It is not something that the Mail app incorporates.

Basically it's nobody's business when or even if someone reads or opens a Mail message.

Sure, but if things got really nasty a "read receipt" would not hold up as evidence in a court proceeding because there are ways of manipulating it. The SMTP standard addresses how to implement them, but as it repeatedly emphasizes they are strictly advisory in nature.

Assuming an email response is appropriate, when I feel the need for a read receipt, I end the email with something like this: "No response means you agree and the matter is closed."

I archive the email for future use and move on. The ball is no longer in my court.