Since everyone else on the beach except Turgoyen is killed, I simply pretend that he is dead as well and keep the book for myself. He doesn't seem to notice or care that the island is surrounded by toxic fog, or that everyone else from the ship is dead, so why should I care about giving him his book? Also, what happened to Narcissus, the head of the Prancing Seahorse, according to Turgoyen? Was he eaten by undead?
I think that the island going all toxic was a casualty of not having enough time or not wanting to write extra dialogue. It's a bit unfortunate, I would have liked to stroll the beaches of Sentinel island as the master of the tower.
The broken waypoint shrine does make it strange wondering how the runners get out. And it isn't even necessary to have it break, because the game already has a mechanism for you to lose your waypoint shrines built-in (after you take over the tower). A working shrine would have made trips back and forth to vendors a bit faster.
