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.
As of Patch 2.3, if you get a message "Interface action failed because of an AddOn", this means that an AddOn interfered with the Blizzard UI in some way. To diagnose this, enter the following into chat "/console taintLog 1" and restart the game and try to reproduce it. If you reproduce it, you can quit the game and search through the file Logs\taint.log for the word "blocked" and mail the log to the author of the AddOn listed there. Once you have done this you can turn off logging by entering the following into chat "/console taintLog 0"

I wouldn't buy Zygor guides. As a player since path 1.10 (around 7 years now) Ive seen a hearty wow community flourish through each expansion. I am a huge fan of the add on, Carbonite quest. It provides a pumped up version of wow's internal quest database. Also, its recommended to research your servers economy for making gold. is a great site for tricks of making gold. Pair it up with and you'll be on your way to making fast gold to provide for all them alts :P

Level your hero. You need to start leveling him from the moment you have 2-3 units. This isn’t necessary. If you have KotG, DH, BM, FS, or AM you don’t even have to wait for units. However, with the help of units, your hero can very easily overcome creeps. Among players there is a certain understanding – creeping. Creeping is the destruction of neutral units in order to gain experience. If you kill a creep you earn gold. A gold number and a plus sign will appear on the screen. Sometimes, you need to kill them in order to earn more gold for building purposes.
What am I supposed to do now? Is there a way to get the curse client working again? I've googled it but haven't found any useful results. Do I have to uninstall & re-install it from scratch? Has the Curse client been taken permanently offline, meaning that it's no longer viable software? Do I have to install a Twitch client and manage my WoW addons from there? If so, do I have to re-install all my addons from scratch, or will they somehow carry over from Curse to Twitch?
You can tell the gold guide users on the AH though. When you are posting things up, if you are the only one and you put it up for say 1000g. Next time you go to post it might tell you to put it up for 1050g, then 1100g. Then 1200g. etc, ad naseum. It doesn't stay the stay it keeps adding the price till it is WAY out of whack with anything reasonable. Still it's pretty good for posting up stuff so long as you know the price already.
Often the name modification (or "mod" for short) is used interchangeably with AddOn. More specifically, a mod is a third-party AddOn that alters or enhances some aspect of the game's interface. Mods can perform a wide variety of tasks, including adding new buttons to the screen, altering the built-in player and party frames. In extreme cases, mods completely supplant the standard game's interface, usually offering more advanced functionality.