I trim the Mosquito the same way I trim the 38. Which is neutral, or a little nose up in the 38, a little nose down in the mossie. I've found that if left on it's own the mossie wants to pull it's nose up dramatically.
I have an X52 flight stick. The throttle on the x52 has these two big round knobby dials on it. These can be set to a position and they will stay there. I use these for my trim. This way when I turn off auto trim, the two dials are already set and the trim just goes to those pretty much pre-set positions.
Due to counter rotating props I don't need to touch the rudder. In fact I don't have the rudder trim mapped anymore. I have the elevator and ailerons set on the stick. And that really just for compensating for damage. Which I am far to busy to do while taking damage so will just turn the auto back on if the trim gets that far out of whack in either plane.
Most of the time I forget to turn off the auto trim anyway.