I really hate the new system, and ignore it accordingly for world building. Also, the term "god" is relative for these endeavors, since powerful demons, daemons, devils, elementals, and even some fey should have the ability to grant spells to worshipers, making them "gods." I know many people here would argue that they should only have warlocks, but I have never seen any actual difference given between the "gods" and non-gods, except arbitrary designation.
Anywho, here's my breakdown of the gods:
Greater (Elder) God - represents a fundamental aspect of the universe, and is beyond the understanding of mortals. Most have many temples, but few dedicated worshipers, with most give homage only when their aspect is going to be immediately relevant (such as giving tribute to Mother Earth before the spring planting). Boccob, for example, is the Archmage of the Gods, and represents the god of magic for mortals
Lesser Gods (usually just called the Gods) - have a much more specific sphere of influence, but also have a greater interest in the mortal realm. Their temples are usually more focused to an area, with mostly dedicated worshipers. The average mortal that is dedicated to a single god, is usually dedicated to a Lesser God. Heironious, for example, is the Invincible Knight, and represents the god of chivalry and valor.
Demi-Gods - gods that were once mortal, and because of this, their home plane of existence is often the mortal realm. This gives them incredible, but localized power. It is possible for a demi-god to rise to become one of the Lesser Gods, but the time-frame for such is usually longer than the lifespan of their home planet. Iuz the Old One, for example, is a demi-god who has gathered all types of evil humanoids to his banner, building an empire that lasts for many human generations, serving as their god of oppression and wickedness.
Quasi-Deities - like demi-gods, these were once mortals who have broken the limits for mortality. Unlike Demi-gods, however, they have very little power beyond no longer aging. They can grant spells to followers, but only those within a set distance (usually a few miles), which keeps the church from expanding. They usually have a small, but devoted following of worshipers (often called a cult). Kelanen, for example, is the Prince of Swords, a mortal who has completely mastered every form of blade, usually spends his days traveling the mortal realm looking for worthy foes to face, accompanied by his worshipers/apprentices (until they die or choose to face adventures more suited to their abilities).