Can I skip installing a dielectric fitting by installing a piece of CPVC pipe between my galvanized pipe and my copper?

Sure.

Yep, KISS is correct. Anything that breaks the contact betwee two dissimilar metals will stop the slight electric current from forming. Soiux makes CPVC connectors and adapter for water heaters, is that what you are working on? http://www.siouxchief.com/PDF/cpvcbrochure.pdf