Is it safe to extract the root filesystem of a Docker.io image and use it in a chroot?-Collection of common programming errors

I have recently discovered Docker, and I think it’s a great tool for managing my runtime environments. However, I also have some OpenVZ VPS’es that don’t support LXC, so I’m thinking about using docker export to export the filesystem of an image, extract the resulting tarball to a directory in the VPS, and then chroot into that directory and run the services inside the image.

Is it safe to do this? What customizations does Docker make to the filesystem of its image (I can see a .dockerinit file in the root directory at first glance)? Any tips & pitfalls of this approach?