It's better to stand sideways so you are working away and towards the body. This allows your arm muscles to work more efficiently. Use only one hand at a time but change hands regularly.
Not good practice with both hands, also maintain better speed regulation and also keep practice where you can quickly rotate your body quickly to change position and hand when they get tired.
Yeah that's not the right crank wheel that's supposed to be on it The one that goes on there is small which gives you more revolutions per turn compared to the big one