We love our research, as at least the silent and slightly sick Sundered Echo can testify. We spent considerable time researching WWI history just to find a place that worked for Echo's character. Initially, the plan was to use a city that was bombed to shreds in WWI, but soon enough it turned out that there were no such cities. Pesky history, eh?

However, if we're curious about something, say Wraith: the Oblivion as much of that stuff you wrote is about, we look it up at need. 
First we'll look such up in the wikia, and if that doesn't answer our questions, we dig deeper. The stuff about those spirits was (in our opinion at least) much easier to read in the wiki. Same goes for abyssal beings and so forth. Considering that some of the creatures you described hold god-like power, they're not all that relevant. Its kinda like how the rules are concerning fighting Caine. Its pretty stupid to even consider it. If we players do not have enough conflict between us to have fun, we're very much certain the friendly neighborhood GMs will have no qualms about rectifying that.