Dr. PC,
I read the first page of this thread and nothing else until this current page, so I apologize if this was covered before.
If you can’t squat without blocks under your heels, you may want to take a look at Dan John’s “goblet squat” video. It can be found on Google Video by searching for “Dan John squat”. That video, and a post by a member here entitled “3rd world squat” - subsequently follwed by a feature article this week - transformed my body from a stiff board to something that actually kind of works these days. My biggest problems were the same as yours - unable to squat deep, painful lower back.
Having practiced the 3rd world squat and goblet squats, I’ve ditched powerlifting altogether, along with the power versions of the Oly lifts, and have started working on full clean and press, and full snatch. Why? Because I can! And I was never able to before.
I’m working with girlie weights right now as I learn the motor patterns (occasionally a power clean sneaks in a full clean session… I just squat anyway!), but I feel WAY more healthy and injury-proof than before.
Something to think about for you.
Dave