You are an idiot. If the shop was ownedby a scottish man would you say morning Scot? (Maybe if his name was Scott)
Or if he was Greek would you say morning Greek? Would you balls, no-one would. And no one is suggesting they would, but the term 'paki' shouldn't always be seen as racist. You said that most people from Pakistan would be offended by the term but I think you're wrong. Whenever cricket is played in Pakistan there are banners of 'Paki Power' are they offending themselves? Their own team?
Saying 'oi paki' in the street would be rude, but not necessarily racist. Jus as rude as sayin 'oi fatty'