Hi Peter,
I'm afraid that my help is going to be quite limited, as for a few months I don't use anymore Debian with Xqt but have changed to pdaXrom. More unstable but quicker.
What I can say about " .xinitrc " is that I used the one created when installing Xqt. I made just a couple of changes that are explained in the page that I made to show some items related with Debian/Xqt.
I am sure that I commented " blackbox " but also I am sure that I didn't try to launch icewm from this file. If you think in the process, the only interest of your " .xinitrc " file is to be able to launch Xqt with just one console where you can write. And the first thing that you do in the console is to call " chroot ", so your original home is lost.
What you want is to launch a window manager from Debian, so, after chroot.
Try to make your " .xinitrc " just small enough to launch the X's from Xqt and have a console. The jump to Debian is done afterwards from this console.
Good luck!!
smuelas