Yay for bumping old threads XD But since this is pinned, I think it's ok?
Stealing corraled horses is okay if your not caught
See, and that's a problem right there. Because someone always sees you while you are stealing it: the HORSE. If you check the CS, you will find that horses have about 15 responsibility ( I don't remember the exact value) and even if there is no NPC in sight to witness your crime, the horse knows and will report itself stolen. So if you ride a stolen horse and arrive at the next town over, chances are that the town guard will arrest you, even if no NPC saw you stealing the horse. So you better get rid of a stolen horse before you get too close to a town.
How do you get your companions to ride on your other horses with you? Do I need a mod for that? Thanks.
Commpanions can't ride your "other horses", since you purchased those horses and the ownership is set to your character. No one else can ride them. About companions riding horses in general...
Without a mod that's pretty much impossible. You could change the Companion Mod in the CS and script a horse, but that takes a large amount of time. Simply creating a horse and setting the ownership to the Companion does not work (believe me, back in the day? I tried that XD)
So you have two choices: you can either search for a mod called "companion horse command" here on the nexus (which requires OBSE and is kind of buggy if your companions tend to teleport after you when they fall behind) or you need to find a companion that already has a horse.