That is not even to mention that I am very curious as to how the Lake of Life was "drained" by blocking the spring.

Yeah, none of this makes any sense. You can't "drain a lake" just by blocking the inflow (and where has all that springwater been going? It's been blocked for what, centuries, so why didn't the water pressure build up and blow the blockage?). He should have had to fill in the lakebed as well, to stop it from refilling with rainwater.

I do wonder why no one took issue with the duke's doings; this was during the time of Icarii rule, after all, and I imagine some would not have liked this.

Icarii even built this city! I don't know; the timeline here is a complete mess.

Well, "Pilgrim" and "Crusader" do fit with what Drago(nStar) does in those books, so I am quite certain it was meant to be him.

So yeah, confirmed - it's total bullshit.