I need just a little down pressure when I go inverted. A trick here is to have more down throw that up throw in the elevator, and this helps it feel more "neutral". You have to play with how much more until you find the point that feels best to you.

I simply mix some right aileron with left rudder to mix out the rolling tendency. You can use the gear switch as the mix switch, so the mix is only active with the gear up. One way to set it up is to fly level and apply left rudder. You want enough right aileron to keep the plane flat as it turns. It will be "skidding" in a sense. Repeat for right rudder. You may also need to mix a little rudder to elevator if it also has a tendency to dive or climb with the application of rudder.

Not sure what radio you are using, but many of the newer radios will have this set up as a pre-set mix option from the menu, as it is pretty common. The 12x has it.