Neil DeGrasse Tyson has told the story on his podcast more than once that the proper adjective form of Venus should be “Venereal”, but, um, that adjective was already taken for a very different meaning…
You do occasionally get other adjectives; this 2012 NASA/JPL article uses “Venetian” (“With his telescope, Galileo started cranking out Venetian discoveries, including how the planet changed its illumination phase just like the moon as it circles Earth”), but of course “Venetian” is normally used to mean referring to Venice (the city in Italy), including by NASA. (Indeed, one is tempted to say that usage from the first link was simply a mistake; even “rocket scientists” sometimes make mistakes.)
“Venerian” saw a fair amount of use in 20th century science fiction, generally back when people still thought it was likely there was advanced life there (“people” I mean, not maybe hypothetically phosphine-secreting microorganisms):
I thought the properties and characteristics of the planet itself were Venusian while the inhabitants were Venutians. Can’t remember where I got that idea though.
Jove and Jupiter are both Latin, though, not Greek like Ares, Hermes, or Aphrodite. The Greek equivalent of Jupiter is Zeus. “Jupiter” is the nominative singular form of the name, but all other forms of the name are based on “Jovis”
I see what you did there, but it’s the nominative that’s inconsistent. The genitive always sets the pattern for all of the other cases. But the nominative, while you can usually give a good educated guess from the genitive, can be anything.