I use superlube on my UCA b/c total chaos recommended me to on the bushings, so that should be okay with your icons bushing
My UCA's utilize uniballs so I can't tell you what to use on your delta joints
The rep is probably trying to simplify things for you and recommends you use one grease for everything.
Either way its good to have both of those greases around. You will need moly for your your driveshafts anyways