I am not aware of any research that supports or guidelines that recommend having an epidural in place for a VBAC. You may wish to ask your doctor for the evidence supporting this practice because you are right that epidurals slow labor, increase the need for oxytocin to augment labor, and interfere with pushing. In addition, one of its side-effects is an episode of slow fetal heart rate either secondary to a drop in maternal blood pressure, the most common adverse effect of epidurals, or just on its own. This could lead to a false-positive diagnosis of scar rupture because a slowing of fetal heart rate is its most reliable symptom. I would add, too, that your prior vaginal births greatly increase the odds of having an uneventful labor ending in vaginal birth. That being said, if you like everything else about your doctor or you have no other choice, you may wish to compromise on having the epidural set but not running any anesthetic through it.
Your ob is right to be leery of inducing labor as it reduces the likelihood of vaginal birth. However its association with scar rupture has to do with whether the woman was induced with an unripe cervix, whether cervical ripening agents were used--cervical ripening agents soften connective tissue in the cervix, but the scar is also connective tissue--and possibly both. You had better find out, though, if your ob is willing to wait for your labor to start on its own or whether your ob will insist on an elective cesarean if, say, you still haven't gone into labor by a certain date or the doctor thinks the baby will weigh more than a certain amount. If that is the case, you will have to see whether your ob will honor your right to informed refusal or find someone else.
So far as using oxytocin to induce or augment labor, not all studies find this problematic for the scar, but others do. I'm willing to bet that the reason for the difference is that in the ones that didn't, induction was only undertaken in women whose bodies were ready to labor and a physiologic oxytocin dosing protocol was used for inducing or augmenting labor. You may wish to ask your ob whether he or she uses an active management (high-dose/short-interval between dose increases) regimen or a physiologic regimen. (FYI: The recommended oxytocin dosing regimen is in the Pitocin package insert.)
I strongly recommend hiring a doula. The largest of the doula organizations is DONA International. The link will take you to DONA's home page. Look at the left of the page, and you will see a drop down menu to locate a doula. You will also find some good general info on doulas, including how to hire one.