After extensive testing by an LS mate and friend of mine, he determined that the "Enhances 'Cure' potency" on the wand only gives +1% Cure Potency. HIs test results and formulas are here: Furen's FFXI Cure Guide
Also, after testing by various people in Ballista, the "Enhances 'Dia' effect" only adds 1 to the DoT of Dia spells, it does not affect the defense down effect in any way.