weighing in VBAC is just a vaginal birth , yes it is politically a "hot topic" there are some special considerations, like increased miscarriage (but that doesn't change care as far management at term) placement of placenta- because there is an increased rate of more deeply adhered placenta if it attaches over the scar- and a very slight increase in uterine rupture rate- about the same as a woman having her 5th baby-- so really not much problem for a normal healthy woman and because it is a politically hot topic there can be alot of fear and emotional charge that can change labor.
Breech birth is not just a single category, there are several presentations for breech and each have different risks, knowing how to manage each type is a skill set and over all there is an increased risk to the baby, this can be a very normal birth as well but does take some special consideration and there is a greater chance of cord prolapse, is the baby presenting in this position for a reason, takes extra monitoring would also be in order-- wiki has a pretty good article on the subject-
http://en.wikipedia.org/wiki/Breech_birth . this is far more of a political hot topic than VBAC and I have known mws who have had births where noting was wrong with mom and baby get into legal trouble (costing some to loose their license or things like legal fees of $30,000 + not to mention emotional wear and tear) and again there is an emotional change and increased fear that can impact the course of labor- increasing the chance of transfer