Is there a way to post (publish) a note from Google Keep to Google+ (sure I don't want to do copy+paste)?
I tried to find support for Google Keep, but I couldn't find it easily to ask them directly.
If there's no way, they should definitely do it.
At this time, the web app of Google Keep doesn't have a button to share notes somewhere else, but there is a one to copy the note to a new Google document. From there you could share the document using Google+, Twitter, Facebook, and to get the URL to share the document using other tools.