We encountered this on one of our projects recently. I think that these two links may help you:
They're both for an older version of Episerver, but I think that the approach is still valid.
My recommendation would be to keep the divs and have frontend deal with it. Removing them might come back to bite you later on....
In order to not render the extra div that is created by Html.PropertyFor, I have implemented the custom content area renderer as per the articel from jon d jones.
However, even though I can see that it goes to the correct part of the renderer, where it should not add extra div, in the end there is an extra div.
Does anyone have a clue how to not get the extra surrounding div?