Back when this game launched I believed bungie had all these secrets built in. I think the quotes and grimoire represents what they wanted to do. Sadly I think the reality is that there is nothing more and that VOG is incomplete but has lore that leaves speculation ongoing. I think destiny represents some grand ideas that weren't completed. VOG is one of them. If you don't believe me just travel the world of areas all over that look like they were meant for something but went completely unused. Naturally I want to believe that it is one grand puzzle like you suggest but over the last 5 months I have come to realize there is nothing hidden below the surface. Hope I'm wrong....