Are there good exercises that flatten your stomach (pouch) without killing your neck or back?

You have asked for a solution that I'm sorry to say does not exist. You cannot trim fat away from specific part of your body by exercising it. You can do a zillion exercises for your abs without melting any fat from that area. However, working your abdominal muscles will make them stronger and thereby firmer and fitter-looking, even if an extra layer of tummy fat remains. That's called spot TRAINING as opposed to spot REDUCING, which we already know doesn't exist.

Training your abs will eventually result in stronger and more well-defined stomach muscles. You will feel a difference, but if you also want to see the difference, you'll need to decrease overall body fat by eating less and burning more calories through aerobic exercise.

Here are three exercises you can do that will strengthen your abdominal muscles without destroying your lower back. Even though they won't melt away a spare tire, they will improve your appearance by making your midsection look tighter and firmer and also by improving your posture.

Pelvic tilt

1. Lie on your back on an exercise mat or carpet with your knees bent and your feet flat on the floor. Place your hands by your side, close to your hips, so you can occasionally check your form. Relax your lower back and head.
2. Inhale deeply, and as your lungs fill with air, let your lower back arch, or raise slightly, off the floor so there is space to slide you hands underneath the small of your back.
3. Exhale and contract (squeeze) your abdominals and buttocks as you gently lower the small of your back to the floor.

This is a gentle exercise that almost every exerciser should be able to do comfortably. However, don't do this exercise if you feel discomfort or pain in your spine or radiating down to your legs. Be sure to move in a smooth steady motion without any bouncing or jerking.

Modified crunch

1. Get into the pelvic-tilt position from the first exercise. Place your hands behind your head, over your ears, or cross them against your chest, whichever is more comfortable.
2. Inhale, then exhale. As you exhale, curl your shoulders and head off the floor.
3. Hold a moment, then return to the starting position.

To help maintain proper head position, keep your eyes fixed upward and slightly behind you. That will help prevent neck strain.

Reverse crunch

1. Get into the pelvic-tilt position.
2. Inhale, then exhale. As you exhale, draw your knees in toward your chest while keeping the upper body and shoulders in contact with the floor.
3. Inhale as you return to the start.

To make this exercise more challenging, start with your feet in the air and knees bent 90 degrees.