This is one of those threads that make me cringe, not because of the subject, but because the topic is one that should be in a by inventation only section. again becuse this site helps spouses of the TG community and the topic is not part of mainstreet life.
But to answer your questions
Question 1 No.
Question 2 No.
I don't see BDSM as mainstram to CD , the meetups, and coventions i've attended and most i've read about do not promote it. It may have a subculture within, but does not seen germain to it.