first of all, i have to agree with PirateGirl for the most part about the levels, and darkhorror you are very stubborn in your beliefs >.> anyway...
i'm a10 and it has taken me ~11000 stacks to level from lv 1. (assuming a 30-40% dig rate, so roughly 45000- 50000 pebbles will max your level^^)
you CAN dig elemental ore, you just need a15 or a10 to dig it efficiently, even then all the JP diggers screw you over >.> you can dig elemental ore anywhere (except kazham area and altepa region)...when/how you get it is... well i'll keep that my secret /grin
here's what i've documented for chocobo digging levels:
/wait 16, a60, about 130D to level up (probably more, sketchy estimate, D = stacks)
/wait 10-11, a60, 230D
/wait 5-6, a50, 510D
/wait 0, a45, 700D
a40, 900D
a35, 1100D
a30, 1350D
a25, 1600D
a20, 2000D
a15, 2600D
a10
as you can see there are 11 dig levels... i guess, PirateGirl, you must have skipped one O.O
I've also dug on my cousin's account to help him, so i can verify the first 7 are correct, and the rest i know are right because i test the area-wait every time i zone (or used to).
there is no skill up "test item," you just need to dig enough items, so if you are digging a lot of "

ou dig and you dig, but you find nothing," you ain't gunna level anytime soon.
you can't dig gold orcmasks in east ronfaure, but you can dig King Truffles.
You can also dig cactus stems in Ngusta, but its like digging up an adaman, orichalcum,phoenix feather etc.
Also, for adaman, orichalcum, phoenix feather, and cactus stems, you should put extremely rare, as i notice its about a 5:1 ratio of black chocobo feathers to adaman
I also keep a list of diggers so i don't dig in the same place... the list has about 100+ diggers on it... all above lv 4 (wait0)... and 33 of them are a10 diggers...best advice for leveling: don't dig during JP time!
oh... how i test it... basically i spam the /clock function when i zone, and when i think it has been (area wait time) seconds, i spam
/clock
/dig
until i actually dig. usually its off by 1-2 seconds, over the area-wait.
a much better way of testing if you leveled is... for example, if you are in Meriphataud Mountains, run down the path until you can dig and mark that spot. If you keep zoning in and out and you run to that same spot, you will find a distance that shows your level. now, if you think you have leveled you can test it by zoning in and out, and try to dig before the spot you marked. if you can dig roughly 5 seconds before the marked spot, you've leveled^^. An example of this test is... when i was a15, i would zone into Sauromugue from Rolanberry, and i was able to dig a few seconds after i passed the arches. After i got a10, i was able to dig before i got thru the arches.
anyways, there's my two cents, i think i'm the first NA a10 digger on my server^^ /cheer
ps. good guide PirateGirl, i just think it needs some touch ups^^