Barry,

I am sorry, but there is nothing wrong with pointing nose down for YS engine. It was in the same sentence that also mentions after run oil, which you should not add to YS engine unless it is a petrolium-free afterrun oil. But if you don't have afterrun oil, pointing the nose down may actually invite some fuel from the fuel tank to come into the engine and undergo oxidation (rust) But if you close off any passage to fuel tank, it's fine to point the nose down.

I've been flying my UCD through winter during the past 2 years. I just bolt on some Dubro plastic skiis. It offsets the elevator trims and CG a little, but hey it's better than no flying.

Sean,

1) Simply mix the 2 elevators servos so they move the same direction and travel the same amount.

2) 3004 is fine for all except rudder. Just make sure your hinges don't bind.

3) I did experiment tip plates on a Funtana 40, and it seems to alleviate the wing rock. So it looks like the theory works. Do a search on wing tips and see the picture of my tip plates.
I have not tried the tip plates on UCD, because it will require more work on this wing. Maybe one of these days...