Just some of my thoughts on the subject:
You and everybody else are correct about form. It needs to be great to prevent injuries, and allow effective lifting. But where I see you are having a hard time is that form breaks (on supra max lifts) when the muscle, or group of muscles, is too weak, so it recruits other muscles. Which is why your form breaks.
Your weakness isn't that you aren't strong enough. It is that your weakest link is the breakdown in the chain. When your form breaks you have to know where is it breaking down and work on that muscle/group.
Fazc is right. Doing high rep work will allow you to become comfortable with your lifts. I feel doing high volume work with lower weights allows me to hone in on my weak points of my technique. When I become exhausted I start to break form, but because the weight isn't heavy, I know where it fails without serious damage, and I can add my assistance work to fit where I am too weak.
Not sure if this makes any sense. I see you feel weak, but I am trying to tell you that you are strong. Just find the weak link in the chain and work on it. Strength is defined by the individual.
Obsessed is a word the lazy use to describe the dedicated