By the way - sorry if it was posted before - when app (like Iceweasel) is started from outside LXDE, context menus work *only* when not in fullscreen. It's not that right/middle click or long tap doesn't work - it *work*, but context menu is just not shown. Switching back from fullscreen reveal "hidden" context menu. No big deal, but is it normal?
Fabry was right, "none" didn't work as a parameter of qchroot. I've uploaded version 0.3.5 to Extras-Devel. It works now, I think.