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.

When it comes to levelling the Priest Class from 1-60 fast, XP grinding locations is only half the battle. You will need to make sure your weapon does enough DPS so that you can clear these mobs fast enough, it should also be noted that monster should be around your level to make sure to gain the 100% XP Reward. The Level your character should be before you start that specific location will be indicated to left in a Blue Color for Alliance [Lvl 35-39] and the Orange Color for Horde [Lvl 35-39]. The Mobs you are looking for in that specific area names are Bolded [Mob Name].
You can’t go wrong with a mage. In fact, Mage was the most popular class in World of Warcraft: Classic due to their ability to farm with ease. Back in the day, the player majority even leveled mages as alts in order to gather gold quickly. In addition to their monstrous ranged DPS, mages also have tons of useful utility. As a mage, you’ll be able to conjure food and water, place portals to the major cities, and even earn gold from doing so.
You will need initial funds to start this way. Buy for cheap and sell for actual price or higher – that sounds pretty easy. But you should have basic knowledge of prices and always track the market. People use to sell for cheap when they need fast gold or don’t know real value of the item. So, it’s your chance to act. If you see anyone selling an item for low price in trade channel, contact them immediately. You should use all of your trade skills to negotiate about the price to make it as low as possible. It’s important ability to communicate. Besides, it’s good to get addons to trade effectively on Auction House: Aux or Auctioneer. They allow you to scan auction, compare prices, find cheapest options, post items quickly, and many other useful tools. It is possible to make your first thousand out of ten gold you have in a pocket.
I think you are referring to the Env Bert strat I have linked. Basically I agree. But you might have noticed that I already had added min power to pet #2, in order to exclude some of the substitutes. Though, I didn’t wan’t to do the same with the Blazehaound (pet #1), because I think the strat is doable also with a suboptimal breed. But maybe you are right and I should just exclude any non-P/P breeds.
It’s important that you levelling in certain areas around your characters level to gain the full XP reward for slaying monsters. Below is a list of all the best location for grinding XP from level 1 to 60, these locations are good for AOE spells and should have plenty of mobs. The Level you should be before you enter that specific location will be indicated to left in a Blue Color for Alliance [Lvl 35-39] and Orange Color for Horde  [Lvl 35-39] the Mobs you are looking for Bolded [Mob Name].
Some even more advanced gold makers might also attempt to monopolize the market. It’s fairly easy if you have quite a bit of gold – just buy out every single item on which you want to have a monopoly on and then reintroduce it to the auction house with your new (and higher) price. However, it’s worth mentioning that monopolization tactic is risky business practice. But where’s high risk – there’s high profit. 

You will have to talk with flight masters in most towns or cities you visit in order to gain access to that settlement's flight path. Flight masters who have a stop you have not yet unlocked will have a green displayed above their head (and on the mini map), much like a NPC with a quest. Unlocking flight paths as you progress through various zones will allow you to pay for a quick ride to a destination you have previously visited. This method of travel is significantly faster than walking or riding a mount.

We’re still looking at how we can best deliver an authentic Classic experience at launch, and in the weeks and months that follow - both in terms of gameplay and community. You won’t see phasing (which is tied to specific quests that don't exist in Classic) or cross-realm zones (which combine multiple realms together) in Classic. However, realm sharding is one of the best tools we have to keep realms stable when hundreds of players are swarming the same initial few zones and killing the same few mobs (like they will be at the launch of Classic). To that end, we do believe that some form of sharding may be helpful, especially in those early days. But we recognize that a cohesive world is critical to WoW Classic and are committed to bringing that to you. Layering in Classic WoW