Plateau Village Transit
You are missing an important, although optional, step at the beginning of the quest. In Bluespire, in the Viamontian tower, is a portal to a dungeon called Viamontian Laboratory, or something along those lines. In this dungeon is a Viamontian Planar Mage (or Portal Mage) that drops a bracelet. This bracelet, when equiped, allows you to use the portal in the bottom of the dungeon, which places you in the basement of the villa in Castle Pietrus. From there, you can complete the Castle Pietrus portion, then move on to the Tumerok Fortification.
Like I said, it is entirely optional, but this is the way the quest was designed to be ran. --An Adventurer 16:09, 24 August 2009 (UTC)
EDIT: And I do not believe the experience on this quest is fixed, simply because of the odd number. --An Adventurer 16:12, 24 August 2009 (UTC)
Carlo di Cenza's Journal
Just a note on your quest overview of Carlo di Cenza's Journal. "That item could then be taken to Antius Blackmoor for experience, who at that time was investigating into a possible Viamontian invasion. He was killed at a later date by the Isparian turned Viamontian Commander Jared Kurth."
Viamontians are Isparians. Isparian refers to humans from Ispar, much like you could call a human from Europe a European. Viamont is just another kingdom on Ispar, just like Aluvia, Sho, Gharu'n, and others.
I've edited the quest overview to be correct now --An Adventurer 16:39, 23 August 2009 (UTC)