i'm not a technical expert in this stuff. Your advice sounds good but I don't see why one wouldn't just choose a weight that they could both keep their back strait and go deep into the actual position. I'm pretty sure that is what they would recommend at my cf gym. So in addition to yelling at people to go deeper they yell about any form/alignment stuff. Usually If I can not go down with a weight *say 225 its because its too much weight for those muscles. in other words it does not effect my form to go down that way with a lighter weight. I don't think i've seen a single person at my gym that can't do a proper body-weight air squat all the way down deep, but people will load up weight beyond what they can get into that deeper position, hence getting yelled at.
I understand where you are coming from, but where I am from, nobody can do an air squat without their butt hunching under them when they are all the way down. This butt hunch is fine when it is body or low weight, but when you are trying to go down all the way with 300 lbs and your butt hunches, its dangerous.
I am starting to like full goblet squats more because you can never go so heavy that your body will lose form, and the natural form makes all the muscles work.
I'd just thought Id share with you guys this routine I made by incorporating Dr. William Wong's minimalist strength training approach. This routine has given me lots of strength, muscle, and success.
Monday
Full weighted chins 3x5/6/7
weighted ring dips 3x5/6/7
Squat 3x5/6/7
Wednesday
Full chin ups 10 sets of 10 or more
Ring dips 10 sets of 10 or more
Deadlift 3x5/6/7
Friday
Full weighted chins 3x5/6/7
Overhead press 3x5/6/7
Squat 3x5/6/7
The 5/6/7 are the reps wong recommends. The strategy is you do 3 sets of a certain weight for 5 reps and when completed 3 sets of 5, you move on to 3 sets of 6 and so on until you get 3 sets of 7, in which case you would increse the weight and start with a higher weight at 3 sets of 5 again.