"Even the fitness chicks in the mags preach the high rep gospel "
That's because with all the juice they're on, if they lifted heavy they'd look like bodybuilders (i.e., too much muscle mass). The only way to keep the size down but have the "hard" look, particularly lower body is high-reps + juice. What most of the public doesn't understand about fitness and high-reps, is the juice part. For non-juicing females, more intense, heavier lifting is required to build the same "fitness" mass.
Regarding empty stomach cardio.
What you burn depends on exercise intensity. For example, if one exercised at 25% and 65% of VO2 max. (25% is a moderate walking pace, 65% would be a moderate jog) for 2 hours and weighed 70 kg, the person walking would burn 72 grams of fat and the person jogging would burn 96 grams of fat. This is fasted state. Not much difference because the rest of the energy comes from muscle glycogen for the 65% VO2 exercise bout, not more fat. In fact, the higher the exercise intensity, the less fat and more carbohydrate is used.
Women in general burn more fat than men during cardio at the same exercise intensity, assuming it is about 50% VO2max.
Pre-exercise CHO feedings will increase the oxidation of CHO, but if the exercise bout is long enough (i.e. an hour +), there is still considerable fat oxidized because the insulin response to the CHO is shut down early on in exercise.
Regardless, it is still best to eat some carbs before going in to the gym, lift first, then do the cardio. Then, eat a meal with both carbs and protein in it right after exercise as most of the carbs will be disposed of in the muscle and liver.
BTW, getting sore isn't only a function of weight-training. Try running downhill sometime, your legs will get sore, but they won't develop like those of someone who squats heavy.
W6