I have analayzed the following position with rybka and stockfish, both of them say 0.00, but something more human friendly might help - what do you think are the plans for each side? is one said playing only on 2 scores? how easy is it to defend as black (even thou it's possible)?

Nd5 is the correct move according to Houdini but more importatantly, it's not about what the engine says, it's about what your opponent can see on the board in front of him. There is nothing wrong with fxg4 because it gives white more options for an attack along the g-file. Black will have a hard time defending fxg4 over the board.