as of yesterday i'm on phase 3, which is the start of the three vendor specific quests. after doing both sets of dailies (shadow warden and druid of the talons), i think i've come to a conclusion on the most efficient way of advancing through this storyline. unfortunately for me, i won't be able to test it out on my main character since she's already knee-deep into the dailies. also unfortunately for me, since i was waiting for a guildie to catch up, i may be behind 1 or 2 marks. we'll see.
but i digress. if i were to do it all again, here's the path i would take:
1. initial phase 1 and 2.i didn't do step 5, so that's where my progress might falter, but again, it's tough to keep track and compare to other people since it depends on the player's choices.
2. turn into druids of the talon first.
3. complete the druids of the talon set of dailies at least once.
4. turn into shadow wardens as soon as i'm able to.
5. complete the shadow wardens set of dailies as soon as i'm able to.
6. turn in calling the ancients.
7. turn in filling the moonwell.
8. turn in additional armaments.
the key parts are turning in each set of 150 marks and steps 6 through 7. if you want to advance faster, i recommend completing calling the ancients first since last i checked it will unlock a daily quest that awards 3 marks. the last two steps are a toss up for me. i believe additional armaments unlocks a daily that awards 2 marks while filling the moonwell daily only awards 1, but the latter quest unlocks the vendor that sells the crimson lasher! so you can see my dilemma, heh. completing all three quests are required to have a shot at zen'vorka's cache and ultimately the searing scorchling.
anyway, that's just my take on the whole matter thus far. if someone discovers an even better way, that's great! hopefully they'll share it with others who have yet to get started on this quest chain.
i'm definitely looking forward to buying my first pet soon! hyjal bear cub, get ready to join my army in about 3 days :D