Idk, if you are at the point where law enforcement is going to a cell provider with a location request warrant you are pretty much already fucked. They know who you are, they know your phone number, they probably know where you live and work

Idk, I wouldn’t carry one across the border any more than I’d take one with me to a drug deal

“Doctor” is a title you become entitled to use by virtue of holding a PhD - you have the option to use it, but nothing compels you to do so if you don’t want to.

Note that the reverse isn’t true - representing yourself as holding a doctorate when you don’t can be a fairly serious crime - if you did for the purposes of getting money from some, then it’s probably some kind of fraud