Dash and space usage for dialogue interruptions, stuttering, starting over

Question

I'm hoping for guidance on several very similar situations, which I suspect are all meant to be punctuated and spaced differently.

Stuttering

How would you write someone stuttering out the word "you"? Here is my best guess:

“What do y-y-you want?”

That is, hyphens (not en or em dashes), and no spaces. Is this correct?

Starting over a sentence

How would you write someone starting over a sentence, i.e. "interrupting themself"? Here is my best guess:

“That’s— It’s more complicated than that.”

That is, em dash, but add a space after the em dash, since it's kind of functioning like a period. Also, the new sentence is capitalized. Is this correct?

(I'm mostly doubting myself on the space.)

Repeating yourself

This gets tricky, because this is kind of like a stutter, but also kind of like the last example, so I'm confused:

“Who—who are the other candidates?”

Have to—have to make it worth it.

“Saying that isn’t legally binding,” she frowned, again, “and it—it’s not that.”

Here I went with em dash, no space, and lowercasing the repeated fragment. What do you think? Do these three examples even belong in the same category?

Answer 1

Part 1: Yeah, it's hard to think of it any other way possible.

Part 2: The dash looks way too long. Alternatively, use ellipses (...) which are often used for a pause in the speaker's thoughts. I typically use dashes when the speaker is stopped against his/her will (Such as sudden death by sniper right before the witness gives the detective the name of the real killer).

Part 3: Here it would seem exclusively ellipses. Again, it's a soft pause. The second and third read like they are occupied by other thoughts and processing the thought and providing immediate comment on it. The first might be hyphened, but I would only do that if it's a surprised or emotionally high energy response.