how rough do you want to be with a boy?
duh. as rough as he'll let me.
truth be told, there is no one, easy answer to this, because no two subs are the same, and my wants and preferences can change over time, or depending on who i'm with. sure, i might like overstimulation without inducing crying right now, but, who knows? maybe at some point in the future i meet a sub who loves being made to cry and i find out that i do enjoy doing that to them specifically.
the simplest way to answer your question is: if it's not rough enough for my liking, then i move on. and if he wants it rougher than i'm willing to give, then i also move on. it all comes down to compatibility, and that's something only time and trust-building can determine.
if what you're hoping for here is a list, though, i guess i can speak generally.
a big reason i go for shorter/smaller men is because they are easier to pin down and keep from squirming. rope helps achieve this–the only times his hands should be on my body is if i say so. this of course means he needs permission to put them on me, which he can get either by my ordering him to, or by asking me, nice and shy and demure, if he can put them there. all in all, his cock is there for my pleasure and entertainment, and i love nothing more than to see a boy reduced to a whiny, frenzied, desperate mess while he touches himself, so he is always welcome to do that, and he better make plenty of noise, while he does. otherwise? he can go swallow his desire, if he's so afraid of externalizing it...
i want to grope and fondle him. i want him to be coquettish, and provoke me into touching him like the slut he's proud of being. in that vein, i want to leave marks. not as a sign of possession, but as a reminder, more to himself than to anyone else, of all the pleasure he is permitted because he is not ashamed of pursuing it. the marks are physical–bites on his thighs, rope burn around his wrists, a dull pain in his ass–but they are also psychological. i want him to feel me pulling his hair when he touches himself in the shower. i want him to smell something that reminds him of me while he's out in public and get all needy. i want him to prefer nothing more than the sound of my voice and the huff of my breath against the back of his neck while i have my way with him.
so, you ask how rough i want to be with a boy?
as rough as he'll let me.