I'm still training for a PPL so I'm not well placed to offer any advice on flying technique. However, I have had three instructors so far; I had five lessons with Cabair and then switched to another school due purely to cost. My next instructor got a place with an airline so I'm now with my third. None of these instructors ever shouted at me and never ripped my technique apart while I was flying. All comments were delivered clearly and calmly and the one time the instructor (Cabair) ever touched the controls during landing he preceeded his action with "Let me help you here" before he lifted the nose slightly before touchdown.
If I may be so bold as offer this note: Many flying schools employ young men and women who have little life experience. Attaining their technical flying qualifications has generally been the focus of their attention for years and all of a sudden they are thrust into a position of relative responsibility and influence that requires good people skills. Some of these individuals are able to handle this but some simply cannot! They are not the gods that (some) believe they are. If your instructor continues to behave this way then request a change and DO NOT feel bad about it.
