How can I install Adobe Flash manually or without giving root access?

Background info: I've locked down my /Library folder so even the admin group can't write (only root can). The Adobe update app opens the password dialog when I click "install". Is it possible to install without giving root access to this executable? The ps command says the installer is running as $TMPDIR/FPUnpackPath/Install Adobe Flash Player.app/Contents/MacOS/Adobe Flash Player Install Manager. That file is a compiled binary (Mach-O). I also found a single dpkg directory: Contents/Resources/Adobe Flash Player.pkg. Under this is Contents/Archive.pax.gz. The file list looks innocent enough, my existing installation seems to have the files under /Library. Would the install be clean if I just run the dpkg file, rather than proceeding with their Mach-O binary? I take it that running the dpkg is safer? (I have a feeling that the Mach-O only does installation-support stuff like making sure the old files aren't in use before replacing.) Please support your answer with evidence, don't merely speculate. Btw, Cmd-I when the Installer app is running will list the contents. Very nice. (See https://apple.stackexchange.com/questions/15658/how-can-i-open-a-pkg-file-manually)