For wp-customer-reviews to be responsive, all you need to change is to make the width and/or height of the css below to NONE:
#wpcr_div_2 { width:none;}
#wpcr_commentform input {width:none !important; }
#wpcr_commentform textarea {width:none !important; height:none;}
these are under wp-customer-reviews.css
This is what I did to make it work around I’m not sure if this is the correct way.