1. Not sure. This seems something environment specific, where you seems to have some restriction with non-root user.
Do you have SELinux enabled? That might be adding more restrictions to non-root user, and if so, you can try disabling the same.
2. Ideally this error shouldn't have anything to do with sample data, but if without that you are getting different error, it could be still related to permission issue. If not, did you try the solution provided in the referred article by adding kestore.init.properties file in the buildomatic folder? If it's there, it will be copied over to WEB-INF/classes and will use that to refer to keystore files. This is only needed if you have existing kestore file and installation isn't creating the same.