Wait until you're level 30 and talk to Dances with Balrogs.
At level 120.
No.
i've never tried it so i don't know if you can.
explorer, warrior, job adv to knight
the same guy that gave u the first job advancement
You can. Go to Perion and talk to Dances with Balrog where you are a Level 10 Beginner. He will make you a warrior instantly. You cannot go if you are an Archer/Thief/Magician as you already have a job.
Go to Henesys and talk to Athena in the Bowman Instructional School. Do her quest and then you'll get your advancement.
no one knows but my guess is yes i am assuming level 170 for 5th job advancement
Go back to the instructor he would have some quests for you
You talk to the NPC who gave you the quest and then go in a map when you talk to her. then fight the monsters and get your job advancement.
Go back to Nautilus Harbor and find Kyrin. She will lead you through the second job advancement. You can find her on the top floor corridor of the Nautilus.
all i know is its in a secret portal near leafre and all the 4th job instructors are there