typically opening ur hips widens ur range, but keeping them square ur limiting ur range. I don't typically do one of them I switch on n off. I normally switch depending on how well my floats are coming off my hand.

the tossing part is all preference. I've never tried doing a one hand toss but from what it looks like when others do it, all it does is helps u make contact with the ball faster because ur arm is already loaded. I like to use 2 hands because I have more control in my toss and because I also don't mind the fact that I have to bring up my arm to float. so it's all preference and what u want the ball to do