Races of Spira

Hello everybody. Since I haven't so far seen a topic on various species that inhabit Spira and you chaps seem pretty well informed-I wondered if any of you might be privy to additional information I haven't been able to mine out of the game script and wikis.

For instance, the Guado who intrigue me the most out of the assorted races...the game tells us Yu Yevon wasn't always the worshiped deity of choice. Did they venerate a singular god prior to their induction into the cult? Is their ability to 'scent' Unsent a unique trait or could it be trained and they simply have a natural affinity for it? What was up with the fiend summoning Guado?

As for the Al Bhed...a lot of fans claim they have a latent ability to manipulate machina and understand it in a manner of the Meks from 40K (warhammer). Certainly, their spiral eye never is really explained beyond Yevonite superstition. Does it hold any real significance apart from being a nifty distinction/symbolic?

Other questions abound* and realistically a great deal of them won't be answered. So please feel free to add your personal headcanon to the mix regarding the non-human population of Spira.

Sorry if any of the above questions have already been covered somewhere in the official material and I'm being an ignorant twit.

*not represented here to save space. Just assume I've covered the bases and then some regards material glossed over ingame for every species.

I like to think that the Hypello were the dominant race, and that all of Spira worshiped the Giant Shoopuff in the Sky.

A couple of things relevant to this thread explained in the FFX Ultimania books is that the Guado have only been Yevonites for about 25 years (because Seymour's father got them to adopt the teachings as leader of the tribe), and the Guado are so good at things like sensing unsent or creating monsters from pyreflies (as seen during the invasion of Home) because they've lived underground close to the Farplane for generations.

Guado also make excellent candidates for summoners because of this natural affinity.

One other thing I can remember at the moment is that it was only a few years before the game that Kelk Ronso and Jyscal Guado were appointed as maesters. This was done as something of a "minority races appeasement measure."