Now this is a book I will definitely buy. Adding more patrons (and spells/classes for that matter) are the things I am most interested in at this point.
Some things I would like to see:
1. The majority of gods should be Swords and Sorcery types but have some quirky ones as well, along the lines of "The King of Elfland" (for a more Tolkien feel) and possibly even one or two that hint at a sci-fi origin.
2. Have patrons of varying degrees of power. Some should be god-like, some little more than petty demons or faeries.
3. A random patron generator.
I'm also involved in this project, and you and I are of a mind. I've started a patron generator -- really more of an idea generator -- that gets you to patron power level, "sphere," Invoke Patron results, and availability of patron spells. The rest is left up to the imagination of the GM -- but running through a few of them, I genned some parameters in 30 seconds and had a fully fleshed out patron in just a few minutes of thinking and writing.
I've proposed this generator to the group, as you've suggested actually, as a stretch goal inclusion.
Here's an example... sans Patron Taint, which is easy enough for anyone to visualize.
Outside the great city of Ugama, the vile effluent of civilization washes into a morass called the Pits. On the shores of this stinking bog live those on the extreme margins of society -- the very rich of Ugama term them Zombi. Among them is a tradition of ritual, idol worship and, some say, untold power. One of the petty gods that the Zombi revere is Myrddin, a spirit, some say a demon, that seems to have taken the Pits under its protection.
In many graven images, Myrddin appears as a composite of creatures found in the Pits -- the body of a crocodile, snake-like arms, the head of the burbur (a snow white man-sized stork that is itself a legend). For those that have actually had dealings with Myrddin, it appears as a formless flow of mud and detritus that speaks in the slow susurrus meanderings of the Pit itself.
Those casting the Patron Bond spell for Myrddin must do so within the borders of the Pit, and, in fact, must first bathe in the filthy outflow of the city and then in the crystal clear waters of the River Rgene, where it exits the Pit. This ritual requires a Fort save (DC 12). A failure indicates that the caster receives a Patron Taint.
When a caster is more than three miles from the Pits or the shores of River Rgene, he or she takes a -2 to Spell Checks to Invoke Patron. Myrddin cannot be invoked if the caster is over 100 miles from the Pits or of River Rgene.
1 Myrddin is insulted by the caster's disregard for its power. (Invoke Patron critical failure results)
2-11 Myrddin's power slips through the fingers like silt in the bottom of a sluggish stream. (Invoke Patron failure results)
12-13 Myrddin's embrace protects his servants. Mud spread on the face imparts a +2 AC bonus for 1d4+CL rounds.
14-17 The mud of the Pit teems with life that answers to the whispers of Myrddin. Spreading mud on a wound heals 1d4+CL hit points.
18-19 Myrddin's mystical powers protect the caster, but at a price. After spreading mud on his or her hands, the caster's next spell result is one "step" higher than the actual Spell Check result. Thus, if the caster rolls a 12 or 13 on a 1st level Spell Check, he or she receives the results of 14-17. A failure is still a failure (and a critical failure still a critical failure). Myrddin's direct influence on the arcane corrupts the caster -- receive a patron taint.