It would be unhealthy to lose weight any faster given the workout you do.The best thing would be to gradually improve your routine by increasing either the time or increasing the speed with which you do your workout.Lunges are good for your thighs, especially if they are weighted lunges (i.e. holding dumbells at your sides while doing them)
It is impossible to choose where your body burns weight. You can firm up the muscle underneath these areas with exercise. The best way is to just lose some weight by controlling your portion sizes and keeping active with moderate exercise.