I agree with Tom, Aaron, & Chris. We compete a lot at our school. You fight how you train. You have to learn how to deal with grinding pressure and do your best to learn to get out without exposing yourself if possible. It's a game. The game is to make the other person give you something. I def feel like there are some douche move, but a sub is a sub.
Pain moves..like calf crushes and arm crushes? We do those on the regular. If it hurts, tap, or expose something else I want, maybe the armbar or twister. Now obviously, it depends on who you roll with. If a day 1 guy walks through the door I would hope you wouldn't put 100% pressure on his face, etc. We have a guy in our gym that loves gag reflexes and Ezekiels. I'm glad he does bc it will be nothing new when it happens outside of our gym. I'm prepared.
It's all Jiu Jitsu. I want to know all of it. I don't avoid doing things bc they suck for the other person. Accept what's going on and make your move. But hey, we have a lot of competitors in our gym, so maybe it different elsewhere.