I feel we really need someone who can dribble or plays direct like he does. I think he has enough quality to be in the squad. Most of the time, we really struggle doing a passing game against lesser opposition who always park the bus, and going direct by someone who actually knows how to keep the ball will normally result in a penalty or clear the defenders to take a shot
Regarding his preference to join Celtic, I can understand it because of the chance to play in the Champions League, IF they qualify. At the same time, seeing how he fares in the Premier League, maybe playing for a club like Southampton or Swansea, is just as much a requirement for City if we really intend for him to be in the first team next season.
I wouldn't want him getting too attached to a club like Celtic. Make him extend his contract or get an option on one of Celtic's potential talents (Tierney perhaps), if we do accede to his request wanting Celtic.