need help in nf plz

ok so i just started my first dervish ive been playing for a while now since factions came out but i had a paragon before which i deleted when he got to lv 20 :P now i need to know when can i change my secondary profesion in nf

Sunspear command post after you do the rescue the prisoners quest

I beleive its just after you reach level 5.

That's choosing your 2nd profession for the first time. To change it it's in the command post after completing the Building the base: prisonners of war quest.

what about the profession changer npc in temple of balthazar?

You have to be ascended/closer to the stars/or the NF equivalent, which involves getting to the mainland and completing the freeing the prisoners quest, or whatever it's called.

No, the quest is called "Hunted".