I'll ignore the boring 'banter'.
As happens at most grounds up here, if you're showing colour/drunk/look like your lost the police and stewards will be all over you. Perhaps you dont go to many games home and away up here but the policing is very different, especially as this will be classed as a high risk game. Of course if you're sensible you'll be fine, but after drinking all day thats a big ask haha. As said above if you're not a wank you'll be fine, same goes for us down at the Etihad. FWIW I dont think there's going to be trouble at the game, its in pubs and the city before/after the game theres a strong chance of some trouble, nothing i'll be overly concerned about though.
R.E return leg - As i'm sure you know playing Juventus and playing Celtic will be completely different, police/celtic/city will do everything they can to avoid us ending up in the home end. Latest i've seen is our fan liason is trying to arrange a fan zone/screens etc. for us down in Manchester.