For some weird reason Warlock used to be underrepresented in vanilla WoW. However, the least popular doesn’t mean that they were bad. Warlocks had amazing damage and some truly unique utility abilities allowing them to summon players or create Healthstones for the whole group. Similarly to Hunters, Warlocks were amazing for solo players with the ability to summon various demons to help them.
Instead of sharding the zones, their plan is to shard the entire continent at launch. In Classic WoW, there are no dynamic spawns and questing in starting zones would quickly become annoying, so it's understandable that the game is all but fun when there are no mobs to kill, but layering will also cause you to see new players, every time you sign in to the game, which is a clear downside of the tech.
Classic WoW is the highly anticipated, upcoming (re) release of the original, first World of Warcraft version, known as Classic and by it's other popular ice-cream like name: Vanilla WoW. Dubbed Retail Classic, or Official Classic by the playerbase - it was finally announced by Blizzard in November 2017, after a lot of pressure from the Private Server World of Warcraft community, since the latter's shutdown of the most popular Private Server called Nostalrius which featured the first WoW version in two separate PvP and PvE servers.
Earning gold in World of Warcraft: Classic is all about optimizing your spendings. Back in the day, your character’s skills were acquired from a trainer, using money. Don’t just buy everything he or she offers! Read the skill descriptions and be mindful about them. Quite a few characters can live through the levelling process without learning some of their utility or damage spells. These won’t go anywhere and you’ll be able to learn them later on.
To get Blacksmithing to level 300 is much effort. It is not that thing to make fast gold. There is always a lack of Blacksmiths though. Enchanters need rods of all kinds, melee classes look for Sharpening Stones and Weightstones with Counterweights, others buy Iron Spurs. Once you have learnt rare and epic recipes, people will always use your service to craft items.
Making "new" guides seems kinda out of place. Not only is there still alot of information from back then available, there came alot of information up for minmaxing available for both leveling and raiding, ontop of various bis gear lists that cover patch progression aswell if necessary. Wether people like or dislike pservers does not make the various information found on their forums less valuable.
Beginning May 15, select WoW players will be invited to participate in a small-scale, focused closed beta test. Players will also get a chance to help put our servers and technology through their paces in a series of stress tests running from May through July—you can opt in now through Account Management and select the WoW Classic beta. Subsequent stress tests will extend the opportunity to even more players. Level caps will also be in place to ensure we’re emphasizing the “stress” in “stress test”
Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.