A horse pasture should have enough space to graze as well as space to run. One horse is 1.5 AUs, so depending on your locality, pasture quality, time of year, etc., you could pasture one horse per 2 acres or more per month.
Yes and no. Yes for if it cribs alot and if its in a small pasture. No for if its in a big pasture and if it doesn't crib alot.
3/4's to 1 1/4 acres per horse.
Depends on how big the pasture is, how many horses. If there are more horses than year round forage, I'd suggest hay. It also depends on what grows in your pasture? Any alfalfa or timothy? Those are really good for the horse(s).
In a stable in the countryside?
There is no specific habitat. Just provide your horse with a big spaceous stall, and it would be best to not lock it there all day. Developes boredom habits, just get a nice grassy grazing pasture! :)
A horse in a good pasture will do.
This is the way horses are: your horse is the "new kid", the lowest in the pasture's pecking order. The gender make up of the pasture has an effect too, as does the gender of your horse; but they will all eventually work it out, it's a natural part of their world and they know how to handle it.
This can depend on the breed of horse and type of work the horse is being used for. Example, is the horse kept for training and competition or is the horse for hacking/riding for pleasure. Stable vs pasture can also depend on the time of year -winter vs summer and of course the quality of the pasture- is there shelter and food.
Yes
It is good for a horse to have another horse due to swatting the flies, and just for the company in the pasture.
No. Pasture the horse on untreated grass. No treatment of any kind, except cutting the grass with a lawn mower.
It can help so long as the horse doesn't have what's called 'pasture heaves' where it's allergic to the molds in the grass.