I kind think you are summing it all up there yourself. What is it you are most worried about in having a VB? Is it being traumatised again, or is it the physical risks to you/ baby? I get the feeling you've already been looking up potential risks with this with what you posted initially and you want someone to quantify things. I could be wrong so I apologise if I'm assuming things here.
Don't feel intimidated by the consultant's status if you have questions and queries here. You seem unsure of what your current consultant thinks is the best course of action and why. Get her to clarify it and justify it, if you can. If she giving you time, then she realises you need it with her, I doubt she'll be annoyed of offended at more questions.
Am I right in saying a) want to feel in control of the situation given your past history
b) don't want to feel like you are taking unnecessary risks.
Is it possible you could try for a VB and then if its not working out, have a plan for a EMCS in a less stressful more controlled way? Perhaps someone else here might be better able to advise you on that, than me... I did think that there can be ways in which you could have lines draw in the sand to go for an EMCS earlier and in less of an 'emergency way', if that makes sense. The term EMCS (like ELCS) seems to cover a multitude of scenarios some of which seem to carry greater risk than others. (One of the recent changes to NICE guidelines on CS was to reclassify CS into 4 categories rather than simply ELCS and EMCS based on urgency because apparently theres different risk factors involved - I haven't read it very well and I may be wildly out in what I'm saying, but I understood it as EMCS having more variance in risk that I think a lot of studies show and it might be something to think about, given your preference for a VB ideally)
And don't forget, pushing for an ELCS doesn't commit you to it. If it helps you resolve your issues along the way, and gets you answers to the question you need do it anyway.