Maybe I'm missing it but you still haven't mentioned what HP the E-TEC is.
Running it slow if it's a V-4 that has a exhaust valve is BAD Very Bad and this valve will not open at RPM's under 4k and will get stuck in the closed position. NOT GOOD.
The E-TEC 2 stroke outboard is a fantastic outboard that will run and run and run on good ethanol free gas. These motors are designed to be run hard and fast. Babying it is generally not a good way to treat this outboard.
But if it's a good one you will blow away all similar hp 4 stroke motors.