I'm always baffled by heavy Calculator users, to be honest. I've never understood the popularity of dedicated calculator apps or widgets, on any platform. 90% of the time you can simply round numbers in your mind, and if precision is necessary for big numbers that's likely a job for Excel.

Same for clock apps. Clock in your taskbar, sure; but who would ever start a dedicated clock app? I barely touch Contacts and always from other apps. Photos is terrible, but that's been the case for a while now, the obsession with hiding the filesystem has degenerated in an unusable interface (sharing in particular is just mystifying).

Of your list, I do use Messages (you don't really get a choice, if you want to receive SMS texts...) and Safari (again, no real choice), as well as the Camera simply because I use it so little it's not worth my time looking for a better app.