You need to level through Nagrand in WoD. Take the Stables/War Wolf. Just FEEL how smooth and fun gameplay is when mounts are treated solely as speed boosts with fancy graphics.
How are players going to interact with the world while mounted?
How are players going to interact with NPCs while mounted?
How are players going to interact with other players while mounted?
That depends on their mount equipment & consumables, like stirrups. But being able to gather mats and interact with NPCs while mounted should be possible. The goal is to give ground mounts a niche that makes them situationally preferable to flying mounts.
How does all of this affect unmounted players?
In-combat mobility buffs would need to be given to non-mounted classes or specs. For your class, I was thinking shorter CD on Blink, 2 charges baseline, and a new targetted teleport that can take allies with you, like Ryze’s ult from LoL.
How do players gain access to mounted combat?
Would some classes/specs end up benefiting from mounts and others not?
Mounted classes would get Mounted Combat at either 20 with their first mount or 40 with Journeyman riding. Non-mounted (foot) classes would still be able to cast limited spells while mounted, like Ice Lance & Frost Nova. Just not the long wind up spells like Fireball, movement-based spells like Shadowstep or Blink, or incompatible spells like Whirlwind or Bladestorm. Prot & Arms Warriors would get a talent choice at about the same level to focus on upgraded movement, like Heroic Leap or Charge, or to become mounted fighters.
What if a player doesn’t have/can’t get access to mounted combat?
All you need is a mount and the right spec. And if you don’t have the right spec, you get a generous movement buff to compensate. Like +100% Ghost Wolf form for Shaman
Would this just mean that players spend the entire xpac riding around on their mount, because that provides more benefits than being unmounted?
If it does for their class. Paladins & Death Knights, canonically, should really be mounted as much as possible anyway.
Would players have to master two incongruent combat systems to be effective?
No. Stay away from Argent Crusade-style “vehicle” combat. Mounts are LITERALLY just speed boosts. Do Rogues have to master two incongruent combat systems because sometimes Sprint is up? Or Paladins because of Divine Steed? This is literally just Divine Steed with 100% uptime for classes where it makes sense. Paladin, DK, Arms/Prot Warrior (talent), Lock, Priest (because let’s face it, their combat move abilities suuuu-huuuck!), and maybe hunter.
What happens when mounted combat meets a raid?
Mounted classes fight mounted. Foot classes take advantage of a quicker ground mount cast time and in-combat casting for ground mounts to help them get around the fight or stay out of the lava in addition to other movement buffs.
What happens when mounted combat meets WPvP, BGs, arenas?
Uh, players play PvP? Movement is faster paced and it’s more fun?
Are flying mounts included? If we say no, how are we going to handle the fallout from players and accompanying drop in stock price?
What fallout? We’re not taking away flight. Release flight at launch. For long distances, flying mounts will still make more sense and players can still use them. For short distances and active questing, ground mounts will be a better choice. There are ideas for flying mounts, too, like variable top speed depending on whether you’re climbing or diving and acceleration so you don’t just go 420%ms right from go.
Where do we place NPCs if players expect to fly everywhere?
Where they would go right now, since players currently expect to fly places. This one doesn’t even make sense.
How does this affect all the content from previous xpacs?
Once you hit 20 or 40 you can mount up for combat on some classes and specs. Like the Nagrand War Wolf. Positively. Amazingly.
“I have questions that were already answered several times in this thread, but I haven’t bothered to look.” is not a rebuttal.
Literally the worst combat in the game. michael-god-no.gif
Always gotta be a MHP. 
Because moving on ground faster than a dragon can fly is beyond stupid.
Cheetah, fastest land animal: 120 km/h
Peregrine falcon, fastest flying animal: 389 km/h
That’s why.
Also, flight is a long-distance travel form. It should be optimized for that purpose. Ground mounts are short-distance travel forms. They should be optimized for that, specifically by allowing combat, gathering, and interacting with NPCs while mounted on a ground mount. That would make ground vs flight a choice based on circumstance, rather than one always being better than the other.
