Q1. Dependent on bodyweight to a certain degree but the numbers that you are quoting are NOT difficult to achieve. The fact that he has not coached himself beyond that level would make me question his validity. There will always be exceptions to this but typically the best strength coaches are going to have been above average lifters themselves. I'm sitting here now thinking of examples from my circle of lifters and from coaches that I have seen in videos or read about on the internet and they are all or have all been at one point, successful. Louie Simmons, Mark Bell who everyone knows or my friends Neil Abery and Dean Mikosz who are both National/European and, in Dean's case, World record breaking drug free lifters.
I'm finding it hard to get my point across here without waffling too much so I'll try to sum up my thoughts:
Question: Do you have to be elite level strong to be able to coach people to that level?
Answer: No but it's damned hard to do if you haven't.
Don't call it a comeback