Annotations and more annotations

Since I'm the first of us to start and I've already been tasked with things, I have to share how hard it is to annotate.

First, of course, I'm really reticent to say things like: have you even thought of a complete rewrite?

More often than not, if I find a logical flaw in my work, I'm all over rewriting completely, but if you don't know me, it probably comes off as meaner than intended. So I attack a couple of things that I find myself thinking about in my own work.

A teacher friend of mine told me to pick only two things because if I attack more it appears like a personal attack, even if it isn't.

So I have to posit this question to the group: how much criticism is too much? Should you reserve careful reading and annotation only to those people you know and love? And if you find the premise of the work to be offensive simply on the face of it, how do you even start to approach that?