Could the empathy power mimic the effects of the fear power?

I would assume so. (Notice my use of the word "assume", meaning that I am not looking this up in any book and am most likely completely, totally wrong.) I think of the Fear power as a limited version of Empathy, rather than Empathy being all emotions except the one or two covered by other powers.

That said, I haven't read either recently, and they may differ mechanically. (Or they could be straight will resists. We may never know.) One might be more effective, or easier to pull off, but I see no reason to disallow empathy from inspiring fear.

Cool.