I haven't followed the whole discussion, so I apologze for just jumping in. But something caught my attention:

 Aaron J. Seigo <aseigo@kde.org> wrote:
> ~ someone (probably me) finishes up containment setting and switching
> ~ someone creates a CustomContainment that lacks a toolbox (by default a
> CustomContainment doesn't have one)
> ~ you use that containment

Aaron, if you haven't announced this to the complainers, I recommend you to do so. I think many are pissed because they think that the toolbox is hardcoded, and when you say that there won't be a remove button, they interpret it as "there won't be a way to remove it". Angst.

I'm one of those who wants to get rid of it. These three sentences made me satisfied.