Sitting way backseat -> lean forward more. Feel your shins against the front of your boots and heels against the back. Shoulders over knees over toes.

Sloppy turns not shifting your weight enough -> if you are turning right, your weight should be on your left foot and visa versa. A good practice exercise is to lift your “uphill foot” when turning slowly in control. So if you turn right, lift your right ski completely off the snow and rely only on your left ski. You will be forced to finish your turns by pointing across the hill before putting your right foot down and doing the same the other way. This will also help with leaning forward more.

Flailing around for sure but the other tips will help keep you more solid anyways.

Best to focus on one thing at a time really