On the Nose dialogue

The definitions of different types of dialogue are starting to blur. I only think it's important to keep them separate because they each have different solutions.

How do you determine when to fix it - when it's too much?

TOO MUCH ON THE NOSE
In Act III it may be okay to say "I love you" but not in Act I.

TOO MUCH EXPOSITION
Some is needed, maybe even required. When is a character explaining too much?

TOO MUCH TELLING INSTEAD OF SHOWING
Sometimes it's okay for a character to say "I'm going to stand up, take my car keys and walk out that door."

Maybe the type of "fix" makes the dialogue what it "was".
Do you say something different (less vulnerable) than "I love you" or do you SHOW it instead?

But the tricky part (who said this stuff was easy?) is to know when to fix it. We need to analyze every single word of dialogue to determine:
- if we are writing visually
- if we are writing believable characters
- if we are (see other thread) moving the story forward.