Guild Wars 2

My Ele is level 40 now and I have been playing around with different weapon sets and doing some of my own testing. What I have not been really able to determine though is the element vs mob mechanic. Is there such a thing or is it just all about the button mashing and luck? Does Fire element inflict more damage against ice based mobs over fire based? Should I be using Earth element skills against air based (flying) creatures? Frost against water?

I did notice that my lightning took down some cave bats much quicker than fire, but that may have just been coincidence.

No it does not, unfortunately.
That would add more dept to the gameplay, and make other lines than fire viable if you want to dps some things.