If it is a young inexperienced horse who needs more training yet, ride it and work with it as much as possible. An older experienced horse doesn't need to be ridden as much. Younger horses, if kept out in the field for long periods of time can get rusty and then will need to be trained over again.
It depends on how hard you are working. Also if you are at a private lesson, you will be put through your paces much faster.
A horse can walk within a few minutes of birth
About five or ten minutes if running.
ummm it depends on ur horse if ur horse is usually calm and is old it may not need to be ridden 4 up 2 a month but that is neglecting it a little bit and if you have a horse with lots of energy it should be ridden at least every week
its "have you ridden a horse" for the English prenounciation. :) mml
Yes, Dutch carriage horses can be ridden. If it is an unbroke horse, start it just as you would a normal horse, however, if you're asking this sort of question, you may wish to use a professional trainer to do it, or to give you lessons. If it is a horse that has been pulling a cart for a long period of time, it may not think anything too terribly abnormal about a person riding them. Again, you should still consult a trainer.
Rodeo
Its ok if all the horses are not being ridden, but they will have to be ridden later.
No
a horse
yes
the oldest horse ive rideen was 30, but the oldest is 40.
So long as there are no serious problems with the horse you can ride it. Many horses are ridden well into their teens and even twenties with no ill effects.
Silver
You can really ride a horse how much you want depends on the horse is it fit? is it over weight and needs excersising? you could ride it every day if you really wanted to but not for a very long time.