No, this has nothing to do with a horse breathing.
Yes. Horses are very sensitive.
There are several reasons to groom your horse aside from the obvious one - to clean it! Horses can enjoy the massage - it is very relaxing for the majority of them. A good grooming after a ride can be a treat for your horse. Grooming also benefits a horse because it helps to distribute the oils in the skin and keeps the coat healthy and helps improve circulation.
Grooming stimulates the circulatory system of the horse and releases endorphins which cause the horse to relax and bond with it's human handler. It also provides a massaging effect which most horses enjoy after being ridden as it helps to relax the muscles.
a horse grooming scrapper scraps of the water and sweat that in on and under the horses coat, it is very usful on a wet pony.
There is information that shows grooming your horse can lower his heart rate. This is especially helpful for horses that are stressed or nervous.
Grooming - the act of cleaning, brushing, or otherwise tending (a horse, dog, etc.) ~fezziwink1013
There are many websites offering horse grooming tips one could use. Equisearch has an abundance of information on grooming horses. They offer a complete section where one could get grooming tips. Pro Equine Grooms offers checklists and tips on grooming which one could find useful on their site as well.
Probably not
For a regular days grooming... probably a curry comb, mane and tail brush, dandy brush (for final brushing to shine up the coat), hoof pick, and if you plan on giving your horse a bath regularly, then probably horse shampoo, horse conditioner, sponge and/or rag, and a towel if you dry your horse. her are the basic things you should carry in your grooming tack box.
Typically self grooming (or mutual grooming) is a pleasurable activity and the participating horses will relax and enjoy themselves. However they also tend to stay watchful and may take periodic breaks from grooming to check for predators or to see where their herd mates are. If one horse has a sore spot and the other horse finds that spot the sore horse will usually send a signal with the ears, tail or head to let the other horse know that it hurts, which usually causes the other horse to move to a different spot.
if you groom your horses in the winter then it will stay warmer and your horse will be prettier and more comfortable
a sponge is used for washing a horse gently, but not grooming it, brushes or combs are used for that