I wanted to give a try at Owncloud but on the standard édition : https://owncloud.com/standard-or-enterprise/
I saw this line: Must share customizations with the Community
What that mean ? That the settings (and passwords ?) of the owncloud server will be published somewhere ? nooo tell me I'm wrong.
You are wrong. Just google AGPL and do some reading.
Customizations are any derivatives of the ownCloud code, including all apps you program and changes you make. This does of course not include configurations like you describe. So yes, you are wrong