Before you can write any sort of code, you'll want to have a tool that lets you edit your AddOn files. However do not get overly distracted with the tools themselves while trying to get your first AddOn created. Any text editor, like Windows Notepad can edit the files. All AddOn files are plain text files. The editors can make the coding and many repetitive tasks easier for day to day editing, but it's often very difficult to learn the tools and try to learn the AddOn at the same time.
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.
Bartender permet de personnaliser directement vos barres d'actions ainsi que les éléments de l'interface de WoW. Il est par exemple possible de rendre certains boutons plus gros voire même de déplacer des pans entiers de l'interface. L'objectif est de vous permettre de personnaliser l'interface à votre convenance, en fonction des informations dont vous avez besoin pour jouer.