Squat: Control the descent a little bit more. Think you could go a little higher (i.e. cut off about a half inch). I believe these problems are inter-related. You'll be able to feel the proper depth a little better when you slow down the descent. Also, your lower back is loose. Spine moves too much. Bigger breath in. Hold it all the way down and all the way back up.
Press: Hands are too wide. Put your index fingers where the knurl meets the smooth part. Elbows should be in front of the wrists slightly. Right now, your elbows are at your sides. Point them towards the mirror. Whatever that hitch you're doing before you press, stop it. Hips drive forward. Keep the knees straight. Watch this video: How to Overhead Press With Mark Rippetoe | The Art of Manliness - YouTube
Deadlift: You need to learn the five steps. Please see this video for a succinct description. How to Deadlift With Mark Rippetoe | The Art of Manliness - YouTube