Even though the guide was developed with a hunter, the guide can be followed by any class.  Except you have to do your class's quests which aren't a whole lot.  I do have full intention to make my guide friendly with all classes in the future by listing all of their steps as well.  There will be a toggle that allows you to show which class's steps you want to see in the guide.  But this is coming later.
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.
Combat is turn-based and there is no time limit on each round in a PVE Pet Battle. You can take your time to determine which spell to use next. Some pet abilities have multiple round cooldowns, while others can do extra damage if certain conditions are met. Be creative and have fun testing which combination of attacks works best against different wild pets!
One thing they told me when I dabbled into computer science back at university was that 80% of the bugs only take 20% of your time to fix. That's why sometimes you see issues persisting for very long times, not because the devs are lazy or incompetent, but because there is usually a priority list of problems, with the severe-but-easy-to-fix ones always taking precedent and the not-game-breaking-but-difficult-to-solve problems being last line.

I recreated my very first character -- a human warrior, because in the last-push alpha test I joined in 2004, there was no Horde -- and logged in. Immediately, I was surprised by how good the graphics actually looked, for being 15 year old textures-on-polygons. Warcraft's bright colors and cartoony aesthetic continue to this day, so all the increased resolution and better-contoured characters in Lordaeron don't really change the game's visual aesthetic.