Nice motor, what are the power specs? Is it sealed?, made for use under water I assume?
, absolutely no point changing to ceramic bearings if they never are in contact with water. If you get water inside your motor you might have a benefit running ceramic, but on the other hand having water between the stator and the rotor is not good (except maybe for cooling).
epoxy is an excellent sealing material, there are some other alternatives like plasti dip, that works well on most electronics. A combinations might be good?
if the power output is high enough(2-3 Kw) I think it will work. Even dough it produces a lot mot drag.
when it comes to drag with a big motor, it is not ideal. But if you have enough power it will work! Here is a funny example I accidently E-foiled the other day with a scarf rapped around the mast.(dont ask:stuck_out_tongue: ). Definitely increasing the drag! It worked as you can see on the pictures to the right.
Propulsion unit is the V1 unit, that several others might be using here on the forum.