Good saves in the first video. Looks like you trailed hard off your brakes and caused your back end to swing around on you. But after the initial counter steer, keep your foot constant on the gas instead of completely lifting resulting in the rear end to stay light. The subsequent 3 oversteer events looks to be due to your foot being off the gas, and just coasting through the turn mid-turn with a light rear end. With more practice, you can be much smoother. Ideally, you can smooth out that turn into a zero-counter, neutral steer with smooth imput of throttle and steering.