I may regret participating in this thread, but... oh well...
This subject opens a huge can of worms. The reason these things are typically of limits is trust and individual tolerance. Many women hate rough sex. On top of that, SPs face enough dangers and enough clients who try to push their boundaries, to typically not want to deal with things like this.
You say you'd never hurt anyone, but does she have any way of knowing that? Especially since so many people who exhibit a fondness for aggressive sex often are those who can and do cause harm. Because of this, even women who may be submissive or like rough sex in their personal lives are usually extremely wary of allowing it in sessions.
I've been told that sometimes a woman may be ok with such scenario with a long-term regular she absolutely trusts. I have also seen a couple of websites advertising submission as a service. So theoretically, it can be done. But trust and safety are paramount.
Because of this, as a general rule, it seems sound and best to ask in advance if a woman may be responsive to this. Or broach the subject with someone who is your regular. It really is the best rule. But then, I can't stick to it without sounding like a total hypocrite because some of the hottest sex in my life has been when a man, um, "increased intensity" while we were together, upon some very obvious encouragement from my side...
I guess the bottom line is that you have to unmistakably communicate that you will respect her boundaries always, and that the situation is such that she feels - and is - completely and absolutely safe. Because otherwise, you really risk getting yourself on a black list as potential abuser - and for a really good reason at that.