The only difference with using VBoxRDP for starting the VM is that it will show up in the log if there are any problems when starting it.
I'm looking forward to your updated script.
PS. I believe you should post a link inside the VirtualBox forum for other s to find this wonderful script of yours. Believe you me there are many others who would like to be able to do this on their linux box but don't know how to code the script.