Definitely yes. Many people eat due to stress not because they're hungry, so learning stress management techniques such as meditation can be very helpful. Also, learning mindfulness techniques can help people distinguish between bodily hunger and emotional hunger. The important thing no matter what you choose is to practice -- twice a day -- and continue it even if you feel it's not yet helping.
Yes. There is not a meditation program that burns calories to help lose weight. Meditation uses few calories. However, some people eat a lot when they are anxious, depressed, or otherwise feeling stressed. If such a person uses meditation and/or breathing exercises for relaxation, yoga, etc., he may feel better, eat less, and end up losing more weight after all.
Absolutely. Studies have shown that meditation can have positive effects on your autonomic nervous system, your immune system and your hormonal systems, thus rebalancing your overall metabolism. Proper abdominal breathing techniques are paramount in achieving the relaxation response. You do not need to be a master. Find someone who can teach you this and then practice it consistently.