The the life cycle cost also depends upon the numbers, the more you own- cheaper would be to maintain them. Agreed that A-330 is more efficient and requires less maintenance but the spares will cost us more, where as the spares of the IL-78 will cost us less.
Suppose we buy 6 A330's, IAF will train 6 sets of crew members to fly them, other crews won't be able to fly them and these crews won't be able to fly other planes. This could cause trouble. There are many pilots and ground crews trained to maintain the Il platform hence anybody of them would be able to handle the Il. Plus it would be cheaper to train the new pilots because of the existing knowledge.
If they can put the probe assemble on the nose than it won't be much difficult to maneuver the aircraft. Frankly i can't comment on this, its just speculation on my part.

As I said the IN will form a sizable air fleet in the coming years and it will need its own refuelers. It cant depend on the IAF as IAF will need their refuelers for feed their own fleet. 12 refuelers for a fleet of 800-900 fighters is less.
AFAIK the USN depends on the ANG and not the USAF to refuel their birds.
I personally would love to see the A330 in the IAF but there should be concrete plans have more of those.