Chapter 5 Intermediate Message Apps: Storyboard

In the main storyboard I added a new view controller and draw a segue from summaryViewController to the new view controller. I found that a pushing segue is translated into a (I think a) modal segue, and the new view controller´s top is under the navigation bar so I added a close button > 64 from top. Is it a bad idea to use storyboarding for this?

No, not as long as you dont contradict yourself in code later.