My opinion is that you are somewhere between getting played for a fool and set up for serious abuse. First, anyone who says you can't choose to walk away from a relationship is either manipulating you, deluded, or both. Either way, it just isn't true. Second, you have every right to have a relationship on terms you are comfortable with, and you are under absolutely no obligation to do as you're told, especially if you're uncomfortable with the situation and haven't agreed to this prior. Third, it sounds like this person at the very least has something to hide, and is probably lying to you.

My personal advice would be to completely hit the brakes, tell her you need to talk terms and limits with her, and make sure she respects both your privacy and your sexual preferences. I, personally, would also demand some reciprocity of pictures and contact info. If she refuses to do any of these very reasonable things I would call bullshit and dump her like a bad habit.

BDSM is awesome, but you don't need to rush into the first person who shows you some interest. The world, and your life, will be full of opportunities. Don't accept someone who will manipulate and lie to you, or who doesn't respect your boundaries and wishes. Seriously. This kind of thing can end in heartbreak or in death. Don't play along.