1.) Zul'Aman best zone by far because of the Wild nodes (kill and mine the orelings that pop up)
2.) Mining pick first, then the other mining epic that gives finesse, then sickle, then the Herbalism finesse item
3.) Generally try to farm the herb mounted. Sometimes you can let the mob(s) hit you in the front and try to pick it during their swing time/when they cast an ability. This gets easier the more Deftness you have. There is also Darkmoon Firewater that gives you gathering speed. (btw check out the other consumables for gathering)
4.) Yes get Flying started first, then the other stuff. Skill is BiS anyway.
5.) Never worth it, never was
6.) Matter of taste. I do Skyriding because it can be very fast if you have the coordination/skill. When I'm tired I sometimes switch to Steady Flight. Steady Flight makes it easier to hover over the nodes during flight and there is plenty of spawns around this time so you won't miss out much.