To help with "power modding" I would suggest just thinking about how real life works. Can you make somebody lift a hand or leg? Can you make them speak or make them feel a certain way? Give your partner that you're playing with time to react to what you're doing. Don't take too many steps ahead of what they could do in their post. Role playing can move pretty slowly. Some people don't mind if you take liberties with their character's to some extent but I would make sure that you've got their understanding as to what you're doing perhaps in a private message etc. ..Just my take on things, hope that helps.