Does anyone have any pointers on how to tell which criticism is valid and which is not during a SR?  Also, if you experience a lot of criticism or rejection in one area of your life during this period, is it definitely a sign that you are pursuing the wrong thing? 

personally, i wouldn't assume it meant i was doing the wrong thing - only that it means i need to review and decide for myself what it the right thing as opposed to simply accepting what i've been told or always thought. these are two very different questions.

"if you experience a lot of criticism or rejection in one area of your life during this period, is it definitely a sign that you are pursuing the wrong thing? "

Not necessarily.  It could be you are supposed to stand up for yourself. You have to judge the source. Are they wiser than you? Better listen. Are they a jack ass?  Better defend.

I agree with Elsa: think about the source of the criticism.

Good points!  Thanks, everyone.  :)