That looks pretty good! I see what you mean by the difference between open quote and close quote. I also see how to add punctuation characters such as colon ( : ) semicolon ( ; ) and exclamation mark ( ! ), and also for when I say exclamation point instead of exclamation mark. And so on.
I think I can figure out how to change the input so that it used the currently selected text instead of having to type into the variable as you did in your demo, and also how to output the resulting string in place of the currently selected text (I've been playing around with some other examples and learning from them.)
So thank you for your assistance! This is a big help!