Yes, Luffy would be defeated. Kenshiro would figure out how to get around the problem of his stretchiness and probably make his ability useless then strike him; I doubt though that he would kill him because he would give mercy saying that "that boy has a good heart" or something of the sort. Raoh would force his chi into the points and destroy him from a distance, because Raoh would have no desire to fight somebody like him who is inevitably harmless; even if they did get up close Raoh would ultimately win just because of how he fights. Toki would beat him but not kill him.