very nice tutorial you wrote but something interesting missing:
how to create a static TAP interface
how to use the Remote Desktop Support (VRDP)
For me its very easy to setup a vmware workstation with a static ip-adress and get it working on both windows/linux but with virtualbox it seems to be a bit more difficult to set up an static-ip adress and to use the Remote Desktop Support so these would be the things of interesting.
would be nice to have a continued tutorial from you