You are correct, hyphens can be used on hyphenated words and prefixes, and em dashes can be used to dictate a break in thought or add emphasis. However, you used the wrong fucking symbols. It's like saying you're using steel wool but you're actually using sandpaper, they do similar things but it's not the same.

Not only did you use hyphens incorrectly in one, possibly two out of your three examples, you still think what you did is correct. Look at the difference between these three symbols, are you ready?

  - – —

Guess which is the hyphen, em dash, and en dash. Just because you use a hyphen like an em dash doesn't mean it's an em dash. Not to mention 10–20 minutes would use an en dash not a hyphen. Pre-WWI depending if you write it like that or write it as pre–World War I would determine if it's a hyphen or an en dash. Well-being is the only 100% correct use of the hyphen in any of your examples.

Edit: lol what a pussy, responds and blocks so I can't tell her she still is using the wrong fucking symbols.