I have a feeling by half squat he is referring to 90 degree knee bend. I could be wrong though. James Smith (aka The Thinker) thinks of half squats in this way, and I know he uses a lot of Francis' work.
I've only read part of the second post, but so far that guy sounds likes a pussy who squeals about fear of overtraining and inadequate preparation as keys to success. No offense.
As for frying CNS, well it's obvious that would be counterproductive, but again, I would argue that a good majority of trainees don't know what their threshold is, and therefore would not recognize where a good point to back off from training would be without indicators of overtraining such as getting sick, disruption of normal sleeping patterns, recurring injuries and stalled gains.
ive heard that francis athletes rarely squatted to parallel.
Lately I've been seeing many different strength coaches saying that half squats are good enough (some say better than full squats). I may test it out next season at a time when my sprinting + plyo volume is high.
Good enough for what?
This information is old, but I just read it again today, and I thought others may appreciate it. I'm posting two different reviews of a seminar.
Here is the link of the first one (I'll post article below)
http://www.charliefrancis.com/2007/01/an_attendees_review_of_charlie.html
bumptidy bump bump
TL/DR
But I will when I get the chance.