NO, only gingivitis. Peroxides was made popular in treating gum disease in the 80's with paul keyes. He was using a microscope to demonstrate lower findings of intraoral bacteria following peroxide rinse intraorally. However, this technique has been corrected by the american academy of periodontology as inaccurate, since the treatment is not bacterial specific and penetration of the pocket depth is questionable.
Usually not. You have a bigger chance of burning your tissues with the peroxide than you do improving your gum situation. Gum disease is hardened bits of bacteria, stuck to your tooth root, under your gums. And any amount of brushing and flossing won't get that off once it is in there. Good brushing and flossing help prevent this from happening, but once it has begun, you need professional help.
See a dentist ASAP. The peroxide will only help to reduce the inflammation at the gum line and have little to no effect on the disease. You should make an appointment to see your dentist for assessment, x-rays and treatment.
A bit. Hydrogen peroxide can help maintain healthy gums once the periodontal problems are treated. Calculus needs to be removed and pocketing needs to be treated. Without professional care first, any medicaments you use are not really going to do much.