Just how much of the game is predetermined?

[Dawnseeker]

So just how much of the game is chance and how much of the game is predetermined.
As i have just found out TYNON selects what i get in my guild chest every before i shuffle.

The guild chest and all chance events are random. The only question is when the random roll occurs (typically before a shuffle), but there's not some guy in a dark room deciding these things.