I'm working on getting this one too but from what I can see, while it's nice having an actually completely free combat bonus that also looks pretty sweet as an Engi, it's still only useful outside of instances and a minor bonus at best. The craftable constructs aren't sellable so there's no way to recoup the costs of crafting this too. Another one I'd recommend against, unless you like having the mech guardians.
Experience the relentless conflict at the heart of the Warcraft saga in this World of Warcraft: Battle for Azeroth Expansion Set. Azeroth paid a terrible price to end the apocalyptic march of the Legion’s crusade. But the shattered trust between the Alliance and Horde is tenuous. As the age-old conflict reignites, gather your allies and champion your faction’s cause.
Assassination Rogues make use of damage-over-time attacks to do the majority of their damage. This makes them incredibly strong single target damage dealers. On top of that, Assassination Rogues have many defensive abilities that allow them to survive a wide range of potential encounters as well as mechanics within raids and dungeons. Their weakest point is the lack of multi-target damage abilities. Their rotation is also very cooldown heavy and is only really effective at dealing with single target encounters.
Each battle that you win will yield experience for each pet that participated. However, deceased companions will not receive any experience (so make an effort to keep them alive by swaping in a different pet). Experience gains are based on your pet's level compared to the wild pet. Defeating a higher level opponent will grant more experience than a much lower level one, but be ready for a tough fight!
Tailoring is a crafting profession that turns various forms of cloth into cloth gear. You can also create some tailoring only mounts. In BfA tailoring has several markets that are good from a gold making point of view. You can utilize the Tidespray linen bracers in the scrapper to get access to cheap expulsom. You can also craft the item level 300/310 tailoring armor. This armor does require expulsom, so it takes a bit more work than the blacksmithing gear. You can also craft bags, which typically is quite in demand as players always want more bag slots.

Darkmoon Faire: The Darkmoon Faire comes around once a month and provides two ways of bonus XP. You can ride the carousel to get the “Whee!” buff (10% bonus XP for one hour). You can also get the Darkmoon Top Hat by playing a few games, which gives you 10% bonus XP but only works during the Darkmoon Faire. Both of these are generally not worth it for the most part, as you spend more time running to get the buff than you gain in XP when leveling.
Level 65 unlocks Greater Invisibility. This can be used to instantly escape combat with any enemy, or reduce the damage of big hits by 90%. Keep in mind, when using Greater Invisibility, you will drop combat, and lots of enemies will start evading and healing back to full Health, so do not use this on low Health enemies if you would survive the hit.

Well, I think, a “wall of of text” is not defined by the amount of characters. To create a wall of text you need two things: lots of characters, and lots of missing line breaks / paragraphs. I’m completely aware of that, and I’m always trying to section and format my texts in a manner that makes it usable for readers ;) I think the limit of 990 chars is not contributing to avoid walls of text. (It’s easy to build a a wall of text with only 500 chars, but I think you got what I mean…)

The leveling guides on my site are essentially speed leveling guides.  My leveling guides are the same guides I use myself to speedrun to 60 on new servers to get 60 server first.  I list many occasions where I tell the player to "die on purpose" to go faster.  I tell the player to skip certain quests, because some quests are just not worth the time/XP.  I list tricks and shortcuts to go faster so you can reach level 60 much quicker.  I am still constantly going through them over and over again perfecting the guides to make them faster and easier to follow.  For the most part, the guide can be followed without the need from other player's help, as the whole guide was made from a solo run anyways.  Although I do list quests that can optionally be done if you have a group.
Excess Potion of Accelerated Learning: Acquired in your Garrison (part of the Warlords of Draenor expansion), this gives you a 20-percent bonus to experience from killing monsters and finishing quests. It lasts one hour, but you can buy it multiple times and use it back-to-back. Alliance players buy it from Sergeant Crowler, horde players buy it from Sergeant Grimjaw. Does not work above level 99.
Good question. Me personally, when I use a new strat from somebody else, I always read thru the strat, and in the case I really need to level some pet, I then (likely) exclude strats that are mentioning things like “RNG”, “risk”, etc. But: I’m always happy (when using a new strat) when I see some detailed infos, so that I can estimate what is going to happen. But YMMV.