I like this spin on things. He’s not explicitly there for a “slow life.” He just wants to “use magic for himself” and find that “home is where the heart is” place where he can belong. Neither of those explicitly involve not using his power or keeping the extent of his power a secret. In fact, it probably works to his benefit if people understand that he both has power and isn’t afraid to use it, so that they’ll think twice before trying to use leverage against him.
On the other hand, if he feels like helping an ally, then that’s cool, too... as long as they understand he doesn’t owe them access to his power. I hope he sticks with his goal and genuinely only gets involved in things because he wants to.