Hi Johninpain
Unfortunately, we can't give you a satisfactory answer about whether you can make too many corrections. Some people write reams and are successful, and some write very little and are successful. Conversely, of course, some people write reams and fail at mandatory reconsideration, as do some that write very little.
The one bit of advice that I can give is don't focus on areas that won't actually earn you extra points. It can be annoying that the assessor got something wrong, but you can put that in the end as a general remark. Go all out for the areas where you didn't get awarded points and you expected to. Yes, there will be a certain amount of repetition.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
