since most people have mounts and most are buyed with gold or crowns and are cheap why not make them kind of like bigger pets. but not like pet training like have an obstical course and you can do it 1 time every hour or so and get 5 xp from it for your mount and you need to get to 500 xp to to get a talent of your choosing it may cast something or boost some thing and what not it not to major but some thing i think it a good idea to get a little more accuracy or boost to hit power or power pips or cast some thing to help a little or give a card KI think about this
Increase speed maybe. But mounts are not with you in battle, and 100 hours to level up once seems at bit unreasonable. Maybe they are stackable hours? A pretty good idea. Sorry if i sound rude.