Having independently developed and implemented a related strategy with success, I would like to point out the specific nuance upon which it is most productive to focus:

You are in disguise, deep in enemy territory, and you will have to maintain this disguise for years yet to come.

The slightest slip-up could reveal you, even if no one seems to be looking, or even if the people you know are looking aren't the slightest bit suspicious. Making things up as you go along is not good enough for the long game; infernal instincts could slip out at any time. Repression just means they'll slip out in ways you don't expect. Anything out of character (and of course your character is a paragon, a saint, always generous and wise) might be memorable, anything memorable might be repeated, and anything repeated might reach the ears of the inquisitor who is less than a byte away from identifying you.

The good news is, you know your own true name and the inquisitor doesn't, so it's possible to get away with indulging your unique nature... so long as you're subtle about it. Identify your urges and pursue any reasonable opportunity to indulge them. 'Reasonable' opportunity means a situation where: 1) absolutely nobody gets hurt as a result of your indulgence ("I didn't know" is no excuse, since the wise and benevolent person you're pretending to be would have known), or even feels like they're getting hurt 2) at least one other person benefits from it more than you do, by their own assessment 3) the urge is satisfied in a way that will linger, rather than dropping off suddenly, to minimize desensitization.

There will be situations where advancing your own interests above all others seems like the only alternative to mewling incompetence, or where you can only choose between who to hurt. Be especially careful at such times, and do not allow yourself to savor them. The inquisitor is watching.