Condensation, rust stain from mitsubishi aircon

Is it ok to run at dry mode? I am wondering if dry mode works as dehumidifier and lessen the moisture so lesser condensation lesser mold?

Is it at the fan coil unit is always two copper pipe inside one insulation sleeve? Is it possible to use one 3/4 inch insulation sleeve for the two copper pipe inside the fan coil unit? Do you mean you can choose you want which side the water to drain out from left side or right side? Thanks