I wouldn't be surprised if they were! Aiba Masaki's (from idol group Arashi) family still owns a chinese food restaurant that literally anyone can go and meet his mother, and that guy makes millions every year. lol They still lived there until a few years ago, and it doesn't have security or anything special. I feel like Japanese fans are generally very respectful about the privacy of celebrities' families.
And about his staff, I remember reading somewhere that they are all employed directly by the Japan Skating Federation. Other skaters such as the Asada sisters and Miyahara are linked to an athlete management company called IMG, that also represents other big names in the sports world (Serena Williams, Nishikori Kei, etc), but Yuzu isn't linked to any company as far as I know.
REAL JOURNALISM RIGHT HERE.