Now, all these cover basically any aspect of life possible and give ample choice to any type of player a character may want to make. The problem is, will they be too much to handle?
Yes.
What can I do about this?
Uncomfortable Fact: The overwhelming majority of players will not care about your homebrew pantheon. The actual number of deities you create does not matter. But the more deities you create, the more likely your players will gloss them all. So I would focus on a smaller subset. What usually works best? None to twelve, possibly thirteen if you opt for using a Baker's Dozen concept.
You said that only a couple of deities will have churches/organizations. And that right there tells me that most of those 60 deities don't matter. If only a couple of deities have a cultus, why is that the case? Does the nation only sponsor or approve worship of a small subset? Again, why is that the case? And why not focus on just those?
I prefer having players walk away with a good, overarching everday life impression of religions rather than a specific list of deities. In a polytheistic context, most people will follow a pantheon rather than a deity. This is captured well, for example, in Eberron where most people are simply followers of the Sovereign Host rather than a particular one of the eight deities. So it is more important to establish what being a follower of the Sovereign Host means for your average person.
IMHO,
the "Slice-of-Life" of your religion(s) does matter. I would recommend putting more effort into that. IME, it is more important to use religion for impressing the prevailing worldview and ethics of a people on the players. You want to show this and not tell. Nevertheless, your "deities" should reflect the sort of stories you want to communicate through play.
For one brief campaign setting I created (for Fate RPG), I wanted a fantastic Pseudo-Renaissance Venice since I knew that one player new to the game we invited would find that comfortably familiar. But the Italian Renaissance is immeasurably influenced by the presence of the Holy Roman Catholic Church, which I did not want to replicate accurately.
Instead, I opted for a religious "Church" based around Seven Spirits of Virtue.* There is a spirit world, and the spirits there embody different concepts. People often variously regard these spirits as angels, demons, devils, or "pagan" deities, etc. depending on perspective and church teachings. The details really didn't matter, and I did not expend much effort into it than I needed. I devised a basic framework for the religion, its episcopal church hierarchy, and basic tenants. Most people attempt to follow these Seven Spirits of Virtue, who are regarded as the closest in being to the One. Churches attempt to teach people to exemplify these virtues. Monasteries may exist for monks to live acsetic lifestyles in accordance with these virtues. I wanted to breed a familiarity of aesthetic and ethics, but not necessarily being identical. For example, there is a "pope" but that figure happens to be female. The Church of Virtue does not condemn sodomy or gays, but it does condemn sexual excess no matter the sexuality, as that fails to uphold the virtue of Temperance.
I explained the basic ideas and then moved on to focus on how religion is practiced, but that was something shown through gameplay. Why? Because really the players only need to know the bare minimum: "people in this area, our characters included, follow or pay lip-service to a religion based around Seven Spirits of Virtue" and "the religion follows virtue ethics embodied in actual spirits."
But "the Church" kept coming up in play. People menion the Seven Virtues in blessings. People may curse using the Seven Sins. The clergy are people who have their own agendas and family connections that are not entirely abandoned. The "archbishop" to the city belonged to a family with close ties to the rival family of that the PCs were variously attached to. Different cathedrals and monasteries had different associated church orders that may not see eye to eye. The PCs dealt with a monastery abandoned on an island that was now plagued with spirits of terror still attracted by the horrific deaths of the monks who died in a sea siege by a rival city decades before. The Seven matter. The Church matters. Ethics matters. Piety matters. The PC remembering the names of the Virtues and the intracacies of the religion does not.
* I did not opt for the Seven Virtues that are a counterpart for the Seven Deadly Sins, but instead a mix loosely based on Aristotle's Four Cardinal Ethics (i.e., Prudence, Temperance, Courage, Justice) and the Three Theological Virtues (i.e., Faith, Hope, Charity/Love).
