Although the Battle Pet Trainer will only offer to teach you your race-specific companion, it is possible to add all of these pets to your collection. You can either find them in your faction’s auction house or you can create a character of the race whose pet you would like to learn. Using your new character, you can seek out any battle pet trainer in major cities. After you learn the pet, you can delete the character; the pet you learned will not be removed from your collection.
I consider myself a purist in that I would prefer classic to be released as close as possible to the original. Where that is on the spectrum of patch content will be up to blizz. I'm also not vane enough to believe that any single state of the game is the "Ideal" location we should be aiming for. There is common ground that we can agree on, and I would welcome more than a few changes as long as they are made in the spirit of keeping classic on the vanilla rails.
5. Spending time actually leisurely talking with others once in a while is actually good for your sanity. If the only entity you're ever communicating with for days to weeks at a time is the demon soul inside of you, it might be hard not to start losing touch and eventually your marbles, especially if your inner demon is especially manipulative (nathrezim, shivarra, succubus, etc) and does more than just constantly offer you MOARPOWAH. However, you might be terrified of actually getting attached to anyone, you don't want the Legion to use that against you. Random, fleeting encounters with complete strangers in taverns and the like is the middle ground you need, to see all of these people and (well hopefully, depends on the crowd) remember what you're trying to protect in the first place, to maybe see children shopping with mama in the market place, or to hear some soldier in the bar talking about his old man back home.
While the avenues for a blood elf to become a demon hunter are limited, that does not mean that the story for this character is limited, regardless of following a particular path. What did your character do prior to the destruction of Quel’thalas? What drove your character to believing in Illidan’s cause so much more than Kael’thas’ own during his defection? What did your character accomplish during their time serving under Illidan and Kael’thas throughout northern Lordaeron, Outland, and Northrend? What does your character think of their people in the wake of Kael’thas’ death?
A new quest will pop up once your first pet reaches level 3. It will send you to either Audrey Burnhep in Stormwind or Varzok in Orgrimmar. These trainers will offer a quest chain to battle specific Pet Tamer NPCs on each continent. Defeating each of these NPCs will reward a nice chunk of experience for your pets, as well a Sack of Pet Supplies (which has the chance to drop the Porcupette companion, among the always-useful pet bandages).