no hard fealings just move them away from each other
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.
This question is really too vague to answer, because it all depends on whether that "smaller than normal" pasture is full of grass that hasn't been eaten yet, or a pasture that has already been eaten down. Also, we don't know whether the horse is being fed on the pasture or in a separate enclosure where there is no grass. And finally, what is "normal" in terms of "normal pasture?" "Normal" depends on where a person lives, the average stocking rate that is allowed for one horse in that particular area, and the size of that horse. Since we also do not know any of these things, we cannot really answer the question.
In a stable in the countryside?
the black thouroughbred in my 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 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.
Yes
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.
No. Pasture the horse on untreated grass. No treatment of any kind, except cutting the grass with a lawn mower.
It is good for a horse to have another horse due to swatting the flies, and just for the company in the pasture.