I've had auto-install working fine with portable.nsd for a few months, with openacs 4.5/postgres 7.2 on Redhat Linux 8 and Windows 2K. I didn't realize it doesn't work with AOLServer.
I've had a great deal of success running web-page based code from the command line, so I expect I'll be able to use your install.xml-based stuff if/when I move to 4.6 (and thereby not require separately maintained installers.)
Unless you've modified db_source_sql_file, I still expect your code won't run on Windows, however.