Soak the rice noodles in cold water for around 15 minutes and drain well in a colander. Then pour boiling water over them and soak for another 5 minutes. Drain, rinse with cold water, and let drip dry. Stir in the oil to keep them from sticking together.
To make the marinade, whisk all of the ingredients together with a whisk until smooth and the sugar has dissolved. Set aside.
Slice the tofu into small cubes. Heat the oil in a pan or wok and fry the cubed tofu until golden brown. Chop the garlic and carefully fry it as well. Slice the scallions into rings and the pepper into strips, stir in with the other vegetables and fry, adding a bit more oil if necessary. Add the cold noodles and sauté. Pour the marinade over the mixture, toss to blend, and arrange the noodles on the plates. Sprinkle the chili powder, chopped peanuts and chives over top or serve them separately. Squeeze the lime over the noodles.