Is there anything worth writing for general use?
So here is where you get to the real problems. You see, before the Europeans show up, most of sub-Saharan Africa was occupied by a patchwork quilt of small iron age kingdoms numbering under 200,000 people, and often basically city states of no more than 20,000 people. Again, see pre-Classic Greece or something equivalent. And with the exception of Ethiopia, which being an empire itself had traded ideas with groups outside of Africa and had its own literary tradition, most of these nation states relied entirely on oral tradition and produced almost no written records and had no direct contact with anything more than a hundred miles or so away. Very little can be definitely said about the beliefs of this period, as they got obliterated almost as thoroughly as the Druidic beliefs of the Britons and survive mainly as oral tradition that has itself probably been influenced by contact with Europeans in much the same way that we can see the underlying pagan tale of Beowulf being influenced by its contact with Christianity. But in general what we are dealing with is a typical animistic society beginning an early transition to polytheism without the benefit of widespread literacy similar to what you see in a lot of the worlds stone and bronze age cultures.
There is almost nothing monstrous in the African mythic tradition that can't be replicated (and usefully replicated) by reskinning monsters from other cultures already documented in D&D as African. This is probably because most fears that give rise to monsters - plagues, cannibals, flesh-eating animals, human psychotics, and so forth - are pretty universal, and lacking literature those monsters didn't have a significant body of uniform lore around them. Think about for example how much we know about the very ancient plague monster we call a vampire is defined by literature of the last 150 years or so. Also, there is a pretty solid theory in my opinion that the great diversity of monsters we know of from eastern Mediterranean myth (largely passed down through the Greek tradition) are artifacts of ancient attempts at what we'd know call paleontology. The Greeks would dig up these bones of say a mastodon, and try to reconstruct what sort of creature it must have come from, and come up with a Cyclops. And further, ancient Bestiaries served as those literary sources for making sense of all the disconnected stories about these monsters. In Africa, you really didn't have much of that, nor did you end up with a heraldic tradition, so you can pretty much rough approximate the monsters of Africa with things like D&D dopplegangers, lycanthropes, ogres, ogre magi, redcaps, imps, windigos, thunderbirds, ghosts, and various dinosaurs to serve as cryptids. Throw in real world animals and an animal spirit template and you are just about done. If you want to get more specific than that, you'll need to dig up a book recording oral tradition, but I suspect that will get you not much further than trying to do the same thing with Gaelic or Slavic fairy tales will get you - a bunch of stories but not necessarily any coherent monster traditions.
African religions on one level are incredibly diverse, representing the incredibly ethnically and linguistically diverse peoples of Africa where you might have 150 distinct ethnic groups in one smallish country. But on the other hand, coming from only an oral tradition the body of lore accessible to you on any on of them is pretty darn small. But there are some general features. They all tended to believe in a universe that had always existed in a steady state and wasn't changing or at least hadn't changed in a very very long time. They all believed this universe was ruled by a supreme deity that was largely remote and unconcerned with human affairs and who was himself not worshiped because it would be pointless. They all believed the supreme deity was served by a vast array of lesser deities with province over things down to individual rocks, trees, or bodies of water, and these lesser deities were themselves not particularly concerned with human affairs but which could at least be bribed or propitiated by making offerings and performing the proper rituals. They all had a scholarly caste of persons who studied the natural world and whose job it was to deduce via a very broad range of divination techniques which deity (or ancestor!) had been offended and was asserting negative influence over the person's life, and to then advise on how that being might be either appeased or thwarted. This role in D&D terms was less clerical than it was shamanic or wizardly, and religion as such had a disorganized character compared to cultures that have reached true polytheism. For example in most polytheistic cultures, the dominate buildings in a settlement would be one or more large temples, serving as the communal center and focal point of worship. You don't really see that in Africa.
There are of course exceptions on pretty much all of those points, which true creator deities, near mono-theistic faiths were most of religious life nonetheless revolved around reverence for ancestors (the chief of which was the first person), and so on and so forth. But in D&D terms, it's not that hard to appropriate an existing pantheon suitable for your fantasy culture, give the Sky God and the Earth Goddess an African avatar, and then largely make the religious life shamans and wizards with few true clerics, and have a fairly close approximation good enough for gaming purposes. And that certainly makes much more sense than trying to import 500 different supreme deities, most of whom had the same characteristics and differed mainly in their names.
I've long been of the opinion that if your class can't serve as a basis for every culture, then it has too much culturally specific baggage. So, if your 'Barbarian' can only serve as Norse beserkers, you might need to rethink. If your 'Druid' can only serve as Northern European shamans, you might need to rethink. If your wizard or cleric can't be a wizard or cleric in any culture, you need to broaden out.
Pygmy peoples, who are basically humans with a 'small' template. That's about it. Again, the idea of things like elves or dwarves living as a race of humanoid peoples that are peers of humans is actually largely a recent literary invention more or less paralleling the development of D&D in many ways. It's not even really a feature of ancient European myth.
Which to me sort of suggests the real African tradition is in our future as the growing literacy and prosperity on the continent leads to them, as Tolkien did, reinventing their own stories.
Equipment, etc. Anything people would like to see?
I feel about equipment very much like I feel about classes. In particular, the range of numbers and attributes you can use to distinguish one weapon from another is fairly small and tightly constrained. There just aren't a lot of gaps in most weapon tables that need to be filled. Mostly you'd be taking the word for "sword" or "dagger" or "spear" in one language and calling it a completely new item, which always to me felt a little silly. A good weapon entry for something like morning star, short sword or scimitar ought to encompass a very broad range of weapons from a great many cultures of the world. And while it might be good to deal with stone, bronze, and iron age materials, in my experience as a DM you'll often be loath to actually apply the penalties for using such materials because it adds mental overhead and makes CR calculation difficult. Humanoids tend to be gimped as it without saddling them with inferior weapons with penalties to hit and damage, or more realistically, with penalties when attacking armored targets.
What in practice is this going to leave you? Well, from my experience very little unless I want to go about faithfully representing African cultures in my fantasy game, which from my perspective is pretty much nonsense or at least well outside my intention. There are no faithful representations of European cultures in my fantasy game, in part because Europe doesn't appear in my fantasy game either.
Nyambe is pretty good for what it is.
