Wanderer is a shorthand term for the idea of using Traveller for fantasy, and represents a number of unfinished drafts on paper with different goals. For example, how magic is used and implemented depends on the person, and the setting is indeterminate. My preference is a low-fantasy (approximately earthlike, and without dragons and wizards) setting, perhaps like the Argonautica, Odyssey, Conan, and Sinbad the Sailor.
In some respects you are contradicting yourself when you state that you want a world without wizards and dragons, and then give some setting examples. The Argonauts run into a fair number of monsters, including a dragon, and, of course, Medea the enchantress. You have Pallas Athena appearing regularly in the Odyssey and Circe the enchantress as well. Conan runs into quite a few wizards, including
Xaltotun, who figures very prominently in the one novel of Conan that Howard wrote,
The Hour of the Dragon. In Sindbad, you have a fair number of magicians along with the Roc.
The you have Dwarves and Elves, who appear prominently in Tolkien's works, while not appearing in your setting sources, as well as Muses that have supernatural powers, with the more capable ones being called mages and sorcerers. Emissaries deliver ultimatums to supernatural powers. You also mention sea serpents, sirens, Djinn (one of the more powerful supernatural beings), and Shamans. The Pict Shamans in Conan pack a pretty good wallop, especially when it comes to transferring the mind of men to animals and vice versa. Having wizards few and far between I can see, but you then counter that with having an entire book devoted to magic.
I do have a question about the following statement.
Disadvantage. Dwarves have an innate greed that interferes with their ability to reason. When in the presence of large amounts of wealth, roll two dice every twenty minutes; when the roll is less than the dwarf's intelligence, the dwarf is unable to make a clear-headed decision until the next time greed is checked.
As read, it appears to mean that the less intelligent the Dwarf, the more likely he is not to succumb to greed. Should it not be the opposite, and the die roll be higher than the Dwarf's intelligence? Then the less intelligent the Dwarf, the more likely he is to have problems with greed.