Here are some notes for the map:
1) Tranquillitatis, though deep and coral-rich, lacks inhabitants of its own; the mysterious, shadowed citadel of Maskelyne casts a gloom across the waters, which even the gnomes of the Taurus Mounts feel little drive to investigate. Certainly the witch-wary margasta tribes, who claim the trifold isthmus between Tranquillitatis, Foecunditatis and Nectaris, believe the dour city's island to be cursed. They believe the same -- and rightly -- of the far shores of Foecunditatis, where many in the montane villages of yaks and goatherds are as human as you or I.
2) Although there are exceptions -- the margasta are every bit as fanatical about mummifying their deceased as Nithians are, and the bhuts of Vedal don't tolerate the competition -- most HM natives have given up on their ancestral burial-customs or cremation practices, in favour of leaving the dead "to lie in state" in some isolated locale, and turning a blind eye to pisachas' comings and goings.
3) They're Hollow Moon rakasta. Rather small and timid, compared to most of the Mystaran breeds, which is why more aggressive species drove them extinct there; their closest cousins are the ocelot-breed from that old Dragon article on rakasta subraces, so I named them for margeys. Simple hunter-fisher tribesfolk, very good at hiding and slinking around, with a deep fear of curses and bad luck.
Hey, it's a nocturnal game-setting! Cat-people certainly belong there.
4) Gutenberg's (lowest left corner caldera on the map) lava-flows follow the same path southward, year after year, building up a long ridge that reaches much of the way to Mare Nectaris while seldom endangering any lives.