Why can't you learn power cleans by yourself? Do you have the book? the progression in there is pretty doable.
You should do chins anyway.
Other than that you probably shouldn't be doing any assistance exercises yet. Have you READ the book ? Particularly the programming chapter ?
Your squats look basically ok. Can't see much of what you back is doing from this angle since the plate is blocking it.
- You're shooting your knees forward at the bottom when you bounce. Get the knees forward to where they're going to be in the early part of the movement and then keep them there.
- Go a little deeper.
Don't worry about your upper back. Just do the program. By the time you get to a 3 or 3.5 plate DL your upper back will be fine.