The amount of right trust is influenced by the dia and pitch of your prop. As you go bigger you will need more. on my pylon racers I run zero degrees on my IMAC airplanes it ends up being between 3 and 3.5. On my electric 2M pattern airplane that runs a 20X15 prop, I am very close to 5 degrees. The test for this is easy but should be done after you get your CG nailed down. Pull into a vertical upline, you will need to get into the right rudder at the arc but once vertical, let off the rudder. An airplane the size of yours should continue 100 feet or so with no yaw deviation. If it does add right until it will do the 100 feet. Atfer that the speed falls and the rudder becomes less effective and torque takes over. Same for up or down thrust, if the airplane tucks, add up if it pulls, add down. Only after everything else is dialed in though. As for my models, I have never had to put in down thrust and on occasion have had to run a smidge of up.