I keep all of my swash mixes at 60%. Then I only use travel adjustments to keep the swashplate level at low stick and high stick. Then I use the pitch curve to limit or add pitch. Then you could use the idle switch to have a setting that is a lot slower with a full battery, then when it becomes to slow at a lower voltage flip the switch to make it a little faster to your desired speed. That way you can kind of keep a constant slow speed at different voltages. Like you said you will have to mess with the pitch and throttle curves to find a good balance for you. I am stumped on the tail except if it is just worn out. I know they don't hold well when they are bad.

Nick