I will have to test this, but I know for a fact that Neriak is like Gorowyn and the adventure writs are handed out by one person at a time. and the NPC that will give you writs in Neriak changes with tier.
but you should be able to. I'm going to test this and have a reply shortly.
EDIT: just tested this in game on one of my FP toons (my 38 defiler) and I was able to get 1 Neriak writ (takes place in Zek, though there were some options for Feerrott, as this site said), and then headed to BBM and got two Gorowyn writs that take place in Steamfront Mountains.
So, even though you are FP based, you should still be able to get writs for Neriak and/or Gorowyn, and build your standing with the Eyes of Neriak and/or Watchers of Timorous (respectively) all while helping your guild grow (or at least earning personal status points).
Edited, Sep 30th 2008 9:55pm by Qwash