I think the do change? teeth do . but maybe Sylar do sent like Sushi but thats not because of tastebuds but because he was turning into sylar slowly so maybe he forgot he dosen't like it becuase Sylar dont maybE?
I always wondered if he could drive...it took until 3/4 the way through S3 to answer that. I now wonder if he has a mobile, he never uses one, he always uses a house phone and he would have NO contacts...poor him...but still...?