There’s a whole list of websites that are trying to compile the working addons for the WoW Classic beta. The easiest one to parse through is Will It Classic. The site has a list of addons — including a search function — and has color-coded each one to signify whether or not it’s working on the beta client. Keep in mind that the client runs on the Legion API, so there are a few semi-current addons that work without any tweaking by their creators.
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.
Battle for Azeroth (110-120) Leveling Tips and Consumables How to level from 110 to 120 as quickly as possible in WoW Battle for Azeroth, including recommended zone order, best consumables, general leveling tips, and best addons. Leveling from 1-60: Questing and Dungeons Recommended leveling paths for new players between 1 and 60 in World of Warcraft. Includes tips for questing zones and leveling dungeons. Heirloom Collections Guide A guide to the Heirloom Collections Tab. A complete list of all heirlooms, how much they cost, which vendors sell them, what currency you need, and more!
Leveling from 58-80: Outland and Northrend Recommended leveling paths for level 60-80 players in WoW. Includes best zones in Outland and Northrend, as well as notable quests and rewards. Leveling from 80-90: Cataclysm and Mists of Pandaria Recommended leveling paths for level 80-90 players in WoW. Includes best zones in Cataclysm and Mists of Pandaria, as well as notable quests and rewards. Leveling from 100-110 in Legion How to level quickly in World of Warcraft Legion from 100 to 110. Includes heirlooms, assaults, useful items, and experience boosts. The Big Bag Guide This guide covers bags from drops, quests rewards, vendors, and professions. Additionally it also covers item type specific containers.