Well, I had some ideas, tried to make them work but with no luck, but now i have a new idea:
I'll use nodes again but they will not be used as fixed navigation line but just as route indicators, what i mean is that when AI will be flying around the track it will check things like: how far is it from wall, how wide is the track at given place, what is ahead, how hard is the turn, and of course if an ship is ahead, can it dodge it (same for mines/bombs ahead)... hopefully this will make them behave randomly, if not, i'll add some randomness myself :3 Ah and they will suffer the same as player: collisions, slow acceleration, etc... I hope it sounds logic xD