I think you are looking at this backwards. You might want to spend some more time learning about the surface area operation and how it expects the surfaces to be selected. A much easier solution in this case is actually to create more surfaces, but in a regular, grided, pattern.
Surface area must have an evenly grided collection of surfaces or it will fail every time. You can't select 1 surface, then 3 in the next row, then 2 in the next row. You must have 2, then 2, then 2, then 2. Or something regular like that. I was able to generate all kinds of paths with your geometry by simply using projected curves and the "Divide Face" tool to slice your surfaces up into an even grid.
The tail and tip get difficult because you have 4 sided surfaces in the center converging into 3 sided at the tip, and into a kind of six sided at the tail. This is very difficult geometry for a CAM system to deal with and is definitely something to stay away from when creating your model if there is any way around it. Try to keep your surfaces regular. That will get you much further than just trying to create fewer of them.
The best tool for your particular model if you want to do the least amount of manipulation is "Streamline". You don't have this in NX2 and if you are doing this kind of work as a serious business it will pay off for you to pony up the money and upgrade to NX8.
Attached are a couple of images of paths created with Streamline. The only modifications to your model are the addition of a couple face divisions near the tail so I could better isolate that geometry. Less than 5 operations in the feature tree and less than 5 minutes of time in modeling.
Hope that helps.
NX 7.5.4, NX 8.0.1.5
Tecnomatix Quality 8.0.1.3
PC-DMIS 2011 MR1