Is it possible for a Zoluren or Rissan citizen to travel overland through Hvaral to Muspar'i? It is my (false?) recollection that only Therengians could receive a passport from the citizenship office?
Yes, you can just go into the Hall there and ask for a passport, there are no current requirements. I've done it with no citizenship and then again as an Ilithi citizen. The gate is at Fornsted by the way, just have the passport in hand when you go through the gate.