#1 I have a G920 wheel and I've played around with a few different rotation rates and it doesn't seem to make any difference with HydroSim. My suggestion is just keep playing with it the way it is and you'll get used to how much to turn the wheel. Hopefully down the road we'll be able to actually adjust that but for now I don't think it works.
#2 @CanYouFoush is right about this. The game's physics aren't completely accurate so doing what they do in real life isn't the fastest in the game. You want to get as much air under the boat as you can without blowing over and it's easier to turn when the canard is down.
#3 The only time I lift is in the roostertail turn or if I fly the boat too high and I need to lift to get the boat to come back down. Other than that it's foot to the floor all the time.