(A very important privacy setting with no corresponding toggle in the UI that can only be set via a configuration profile is the option to not auto sync your list of recently emailed people to iCloud (“Disable recents syncing”). This leaks your email contact history and social graph to Apple if you have iCloud turned on, even if you aren’t using an Apple email account and aren’t using iCloud Contacts. AFAIK there’s no way to disable it other than via configuration profile.)
This is what I do.
One quote from the article: “Your iPhone, and a billion other Apple devices out-of-the-box, automatically run famously insecure software to preview iMessages, whether you trust the sender or not,” said security researcher Bill Marczak, a fellow at Citizen Lab, a research institute based at the University of Toronto’s Munk School of Global Affairs & Public Policy. “Any Computer Security 101 student could spot the flaw here.”