Ok, so here is where I am with this:
- yes, editing the config.php file will allow you to use a different folder as the data folder for owncloud (restart apache)
- some things to be aware of when moving files into this folder (also outlined in some of the resource links provided by alfredb
- symlinks are not needed
- how you copy/move the files into the folder is important. depending on the way you move/copy the files you may miss moving/copying some hidden files
- you have to chown the folder/files recursively to www-data
- you also have to rescan the folder(s) so owncloud picks up the changes:
sudo -u www-data php /var/www/owncloud/occ files:scan --all