These are some generic principles when dieting:
1. The fatter you are the more energy you'll have.
2. The larger the deficit the less energy you'll have.
3. Generally, adding insane amounts of activity when dieting is not smart, even if you're fat.
4. If you're small (like 135 lbs or less), you probably have to add some cardio to have fat loss at a decent rate.
5. There is no reason to switch from low-moderate reps to high reps. Heavy weights helps to maintain muscle mass.
6. If you want to go from couch potato to fit guy/gal, you should look long term and do a moderate/sustainable diet that involves a lifestyle change. You're not going to lose weight and get fit fast.
7. Rapid fat loss to start a long-term diet could be helpful with dietary compliance.