Don,

On G2 I have no issue with using rudder trim for the perfect knifeedge, but on a real plane your just adding drag.

As to altitude changes on the race course, the trick is to not have any .

If I come out of turn one and my plane climbs I may need to add weight to my left wingtip. If it comes out high because I did not bank enough before pulling elevator, I will hold that higher altitude. By correcting your altitude you are once again slowing your plane down.

I think most people have a line around the course that they prefer. For me, its about 5 feet above the pins. However, that seems to be where most others like to fly also and in heavy traffic you are only looking for a midair. Get use to flying the course at all altitudes, because you never know when you have to avoid traffic.

If I want to change my altitude I tend to do it on the turns by either overbanking or underbanking before pulling elevator. Be carefull on the overbanking one if your low