Hi,
I guess you are referring to Revo on a
fixed wing, not multirotor?! Don't know if Autotune is applicable here. Also, it is desireable the plane to be trimmed fine for manual flight (
correct CG is really important!). Small imperfections in control surfaces trims will be handled by FC in stabilized modes.
There should be something wrong with your PIDs, did you changed default values? I have built two planes so far with Revo FC, Wing Z84 and MiniTalon and maidened them directly in Attitude with default PIDs, both successfully. Further tuned PIDs in-flight through TxPID module. But the defaults were fine and planes were easily controllable.
Attitude mode doesn't keep height automatically, neither for multirotors, nor for planes. It just levels the UAV. If you see drifts in Attitude, you may have the FC not perfectly aligned when mounted in the fuselage. Play with
AttitudeSettings / BoardRotation to cure the undesired drift.
Violent vibrations can disturb gyros and accelerometers, do you have a lot of vibrations with motor running?
Here is short clip of MiniTalon - takeoff in Attitude mode with 20% evelator, some flight and landing in Rate.
And its maiden in Attitide with default PIDs. Bad roll to the right is caused by 100% throttle leading to massive torque roll