For all these videos, can you get your camera at roughly hip height? These angles are not ideal for seeing what's happening in your lifts, especially your squat. That said...
Squat: These are a good half foot high. You need to get lower, hips below the tops of your knees. You'll have to take some weight off to do this. You'll probably have to go back to 275. If you have to go even lighter to get all the way down, do it. I can also say that you are not really getting tight at the top and bracing yourself before you go. Take a big breath, squeeze your chest up to set your back, then squeeze your abs, and squeeze your quads too. Then go.
Power Clean: You have an arm pull. You are bending your arms right before you jump. Repeat the step in the learning process where you jump with the bar in your hands, keeping your elbows locked / arms straight. This is how you have to jump when performing the movement. Arms don't bend till after the jump. Your stance is also a bit wide, and gets wider as the set proceeds. Narrow it -- 8 to 12 inches between the heels.