Yes, but it does not get very long, just about a few inches so it looks like it stands straight up on the neck. Most people descirbe their mane as a mohawk mane, because it sticks straight up and doesn't grow long like a horse's does.
Not all wild horses have erect manes and not all domestic horses have 'floppy' manes. Some wild horses developed erect manes to help with camouflage and cooling. While domestic horses and other wild horses mainly have floppy manes to help shoo away bugs.
Yes, bay do horses have black manes or very very dark brown.
No, not all horses have manes. Some horse breeds, such as the Akhal-Teke and the Andalusian, are known for having less prominent or even absent manes.
no, all horses have manes unless the owner has decided to 'hog' the horse (cut its mane off) or it rubs it out on a fence etc.
No. Buckskins can have black, brown and dark brown manes and tails.
Horses and ponies have manes.
yes, compared to up-kept domestic horses manes and tails.
Buy a book and it will tell you. Most good books will have how to braid their manes and tails they should also have pictures to guide you.
Bay horses can be any size, as bay refers to a coloring of horse, in which their body is brown, and they have black manes, tails, and points.
Braid a horses mane like a persons hair, there isn't really anything different between the two.
Horses developed manes over time as a way to help shield themselves from flies.
No, horses manes are generally long unless thinned, cut (which you shouldn't do or it will grow back very thick) or hogged (cut very short like a zebra and it sticks up). Whereas a Zebras mane stays hogged all of its life.