Odds are very high, almost 100%, that he's a male with what you've described and the fact that he's a pied. The "boys have brighter cheeks and no tail barring" adage is only true of grey bodied cockatiels, once pies get thrown, the norm gets thrown out. I believe this can also be the case with lutinos. It's much more about behavior than appearance, from my experience.
Not only that, but he sounds like a huge sweetie! What a lovely repertoire of sounds he can make at just under a year