Although most of your questions have been answered but here is my bit,
1) initial cost is not a factor = So no problem
2)city win both in city or highways, ac on or off. I used to have a trip of chakwal to lahore on my city in RS 2300, we used swift for same trip and it costed me around RS 3000.
3)City is more comfortable and spacious, with better seats and leg room both front and back.
5)Dont have a clue regarding resale.
Now my other observations,
1-Swift is zippy and thirsty compared to City.
2-Swift has better built quality especially of interior, atleast that what we get in earlier batch.
3-Swift is better value for money, got immobilizer, keyless entry, genuine suzuki alloy wheels plus good tires (DLX), high mount lamp. City lacks in this regard, i have a auto city and it doesn't have trunk lamp. Come on you pay 1.4 million for a car and get a car without trunk light. In the given price city lacks keyless entry, immobilizer, alloy wheels.