[Quoth]

hyphenated words: child-like
USA aside, instead of commas, uses em dash—with no spaces.
UK aside, instead of commas, use an en dash – like that – with spaces. Note they are not hyphens.
Interrupted dialogue always an em dash
"I say—"
The anvil had fallen on Wil e Coyete again.

Convert to epub and edit the file to be as you desire and convert the epub to PDF.

The "regular" hyphen is never used where commas or brackets are used, but mostly to split or join words.

Maybe you want an en dash with spaces and the mobi source has used the USA style em dash with no space.

There are some other sorts of dashes, but the hyphen, en and em are the most common kind.
- hyphen
– en dash
— em dash

Convert to epub and use the Calibre editor with “smarten punctuation set”, but not a simple find and replace as you want to leave any em dash at the end of dialog alone (I see what quotes are used and if it’s then I replace —’ with ¬’ (similarly if " or ”), then replace all — with a spaced en dash. Your OS will have a method for entering these. Then I replace ¬’ with —’
There are smarter ways with regex.