Unlike many other classes, writing a demon hunter carries with it a necessity for a call to action for the character in question. For those writing a night elven demon hunter, this call to action is wildly different and varies heavily from each individual whereas those who are writing blood elven demon hunters have only one true avenue for their path: those sent to Illidan Stormrage by Kael’thas Sunstrider to train to become demon hunters.
No he's just not paying attention. The wanted quests are built into both the leveling guides and the "Zandalar Forever" achievement guide. They aren't in the rep guide because they are not repeatable and by the time you hit max level they should be done. You'll also notice the rep guide doesn't contain every single possible completable quest that rewards rep. It is designed to focus on repeatable objectives, world quests, large quest lines, and missions.
World of Warcraft Classic lets you play the game as it existed almost 15 years ago, upon the release of the 1.12 "Drums of War" update. Blizzard says it considers that era to be the correct balance of the game resembling its original launch state while also having ironed out some of the rough spots of launch. This version is also including some updates under the hood, like modern server infrastructure and Battle.net social features.
To get back to Classic for a bit, this is what I think is happening. Players who prefer the old ways (and full disclosure, I'd count myself among them, but to a smaller degree than most) complain/talk about the negative sides of modern WoW and Battle for Azeroth in general. While they do this they also talk about how things were better before and often mention Vanilla as a reference point. People who enjoy BfA now feel attacked by this and so they retaliate. Hence, liking Classic means you either have nostalgia goggles on or have no idea what you're talking about and will hate the same things you say you want 2 weeks after you start playing it. It's an amazing thing, where literally each side is doing to the other what they feel is being (wrongly) done to them. I feel like writing this is the most redundant thing I've ever done, and yet I also feel that it needs to be said, because it seems some people just don't get what they're doing, or at least I hope they don't (some do and are doing it on purpose but there's trolls everywhere so there's no point in even discussing them).
2. Your DH needs supplies on a regular basis. They can only carry so much food, clean drink, medical potions and whatever else they want/need at a time. It's pretty realistic that they would need to visit a market every so often, and large faction markets will have the most variety and types of items to choose from. (My DH has been a recluse in the wild for some time, and she is stinky, dirty and has eaten some questionable stuff. This isn't really ideal and a Dalaran doughnut would be pretty flippin nice.)