Wait, /sit to trigger crits is p-server thing? I distinctly remember people saying that if you sit, you will be crit when I played 1.12 Vanilla. On top of that - there’s that pally that one shot Kazzak in early Vanilla because he stacked a shitload of reckoning when it didn’t have a limit - it’s not inconceivable that he did it without /sit to trigger crits, but it would take him so, SO long to do that without /sit.
Swim Speed Potions (used especially at lvl 37 for Faldir's Cove in Arathi Highlands and lvl 57 in WPL). Try to get multiple stacks of these. I also recommend keeping a stack of these always in your bags. You will frequently pass rivers and lakes and can use these potions to pass them faster through out the guide. Please note that these potions do not stack with Druid's Aquatic Form and Glyph of Aquatic Form.
As of right now, there are eight confirmed Allied Races, though Blizzard has said it’s open to the idea of adding new allied races in future content patches or expansions. The Horde will have access to the Nightborne, Highmountain Tauren, Mag’har orcs, and Zandalari trolls. The Alliance will be able to recruit Lightforged Draenei, Void Elves, Dark Iron dwarves, and humans of Kul Tiras.
Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.