I know he plays there for NORTHERN Ireland, that does not mean that is his best position. I would only ever play him on the right if Rosenior was getting overloaded and we need someone with a bit of energy and defensive ability to help him. I can't believe people want goals and are suggesting playing a box to box midfielder on the wing...
As for your last sentence, that is wrong. Play Carlos Puyol up front and see if he is as effective as he is at centre back.
Ash was in the team for his leadership, organisation and motivational skills. Harper was meant to do the same thing. Geovanni played further up the pitch and would never be able to play in a central midfield that only had 2 in there.
Cairney is a player that will retain the ball and play simple passes. He is never going to be Iniesta who dribbles past 4 people then scores or plays the killer pass. Think of him as Xabi Alonso, Alonso is not used as the main creative outlet in the final 3rd, there is always someone ahead of him to do that. At Liverpool there was Benayoun (a very underrated player) Riera and Gerrard who was playing just behind Torres. At Real Madrid he has the likes of Ozil, Sahin, Di Maria in front of him creating things.
We have seen how good Cairney is at playing the long pass and switching the play. He should be used for that rather than people expecting him to play the killer balls that he doesn't have the quality to make (yet).