I agree with having horses being summoned by farmers and ridden by all. The only problem there could be with summoning is that you'd have to meet with whoever you want to sell to/buy from, and I don't think a GTP to spawn would work while holding horses.
Equine Equality is a must. All access or no-access, and I think it should be all.
Can't have some people derping around on mounts while others hoof it on foot, or everyone will just go farmer.
Yes, give horses to everyone!
It's simple! Horses will replace the useless summon bat for farmers lvl 60 skill. This will give farmers a way to make money besides leather. Everyone should be able to ride horses at some point (whether it's a skill you have to lvl to get or just inherent at lvl 1.)
Summonbat should stay, just to keep farmers summoning all passive mobs that aren't found very easily in Herocraft (except wolves, I think they should be summonable, but that's for another thread).
Maybe smith and/or alchemist can get forge horse armor and saddles as they will be in high demand after this.
Maybe have horse armor take 9 or the material, and saddles take 4 leather to make?
Maybe a certain level like WoW. You start with a slow mount and higher levels get a faster one?
No, I think you should be able to ride any horse at any level. Some horses are already faster, have more health, etc. than others, and if a farmer only breeds those, lower levels would have no chance at riding a horse until 65.