Is using diluted essential oils as a body spray considered safe?

It depends: It depends on where you're spraying them, in what concentrations, and whether you personally tolerate them. If you have sensitivities towards what you're spraying, you could develop a skin or other tissue reaction. You want to dilute essential oils into a carrier oil to at least 2% (or less). http://www.aromaweb.com/articles/dilutingessentialoils.asp.