OH Fun, Fun, Fun!
All of my characters have a history of some form or another from beginning and before spawn cause otherwise I don't see them as having a personality. Your history MAKES your personality, that's how the real world works, at least. Though I do keep it within Cantr grounds.
One of mine was raised by toucans but at that 20 mark he was "visible" (I guess) and grew to know people. If you know the character or heard him say of this, you understand him SOOOOOOO much better. He can speak the language from spawn cause birds mimic others. That was my rationalization, at least.
Another of my characters had something of a "visit" 15 seconds before his spawn. He is usually deemed crazy by the Cantr elitists as anyone with "visions" and other such things of that nature.
I've a few with odd talking behavior. When a "character" pokes at them for talking funny, I always wanna smack the opposite player in the mouth for lacking in their subtly. If you are gonna make fun of the way I RP, at least have the decency to OOC: "You RP shitty" so I can report you for being a shitbrick.

I see absolutely NOTHING wrong with having histories within Cantr and when people play the "I've never heard of such things" line, I usually outright ignore the behavior and shove on with my own thing, anyway. Those types of players will always find something to nitpick at, anyway.
One should TRY to keep things "Cantr specific" if only to prevent the people who hide behind the CR from smacking you in the mouth with one of their precious CRB "reports". I'll also note that the people who do such things break the CR in HEAVY HANDED ways so just ignore them and go about your way. Cause, again, these people will nitpick you to death regardless.
Subtly, as said by many others, is your friend though. Many characters and/or players I RP with have littler problem with my additions of history as its slid in their casual like, as Hermi said.
I'll also note that the spawns I make with less history, or none at all, I find boring as everyone around them is usually some form of hollow shell (This is half my characters and the ones I want dead.) which means not much can be built off of them. You can't build a personality off others when most others are copy-pasty and only interested in some very specific things.
Oh and a small note to the OP: Your Blackrock area character needs more subtly as even I went "Jesus Christ".
